| Q |
| Quaker City Airways | California | | | | | Burbank | 1948 | 1961 | Supplemental air carrier. Renamed Admiral Airways. Operated Boeing 307 Stratoliner |
| Queen City Flying Service | Ohio | | | | | Cincinnati/Northern Kentucky | 1940 | 1970 | Operated Beech 18, C-45 Expeditor |
| Quicktrans | Virginia | | | | | Norfolk | 1950 | 1994 | Navy cargo virtual airline |
| R |
| Ram Air Freight | North Carolina | | | REX | RAM EXPRESS | Raleigh Durham | 1982 | 2008 | Operated Grumman Cheetah, Piper Seneca, Piper PA-32 |
| Ramp 66 | South Carolina | | | PPK | | North Myrtle Beach | 1991 | 1994 | Operated Beech Baron, Beech Bonanza, Cessna 402 |
| Ranger Airlines | Texas | | | | | El Paso | 1968 | 1970 | Scheduled third-level services |
| Rankin Flying Service | Oregon | | | | | Swan Island | 1927 | n/a | Founded by Tex Rankin |
| Ransome Airlines | Pennsylvania | | RZ | | | Northeast Philadelphia | 1967 | 1995 | Feeder flights for Allegheny Commuter (1970-1982), Delta Connection (1984-1987), Pan Am Express (1987-1991) and Trans World Express (1991-1995) |
| Rapid Air | | | | | | | 1965 | 2006 | Cargo operator. Known as Sparta Aviation Service |
| Rapid Air Lines | South Dakota | | | | | Rapid City | 1930 | 1933 | Merged with Hanford Airlines to form Hanford-Rapid Airlines |
| Rapid City Airlines | South Dakota | | | | | Rapid City | 1928 | 1929 | Established as Pioneer Airways. Operated Curtiss Jenny |
| Raritan Valley Air | New Jersey | | | | | Manville | 1966 | 1968 | Operated Beech 18, Beech Baron, Piper Apache |
| Rasmark Jet Charter | Texas | | | | | El Paso | 1984 | 2000 | Operated Learjet 25, Falcon 20 |
| Raven Air | Alaska | | | | | Anchorage | 1987 | 1992 | Operated Cessna aircraft |
| Ravn Alaska | Alaska | | 7H | RVF | RAVN FLIGHT | Anchorage | 2014 (traceable to 1948) | 2025 | Shutdown due to travel disruptions caused by the COVID-19 pandemic, |
| Ray Petersen Flying Service | Alaska | | | | | Bethel | 1937 | 1945 | Acquired Bristol Bay Air Service and Jim Dodson Air Service |
| RCR Air | North Carolina | | | | | Lexington | 2007 | 2014 | Operated Embraer ERJ 145 |
| Reading Aviation Service | Pennsylvania | | | | | Reading | 1966 | 1966 | Operated de Havilland Dove, Beech D18S |
| Rectrix Aviation | Massachusetts | | | | | Nantucket | 2005 | 2019 | |
| Red Arrow Flying Service | Florida | | | | | Miami | 1917 | 1919 | Renamed to Chalk's Flying Service Operated Stinson Voyager with floats |
| Red Baron Airlines | Florida | | | | | Palm Beach | 1979 | 1980 | Renamed to Florida Commuter Airlines |
| Red Carpet Airlines | Florida | | | RED | | Clearwater | 1978 | 1981 | Renamed Aerosun International. Operated Convair 340, DC-3 |
| Red Dodge Aviation | Alaska | | | | | Anchorage | 1969 | 1972 | uncertificated carrier flying Lockheed L-100 Hercules. Subsidiary of Flying W Airways |
| Red Way | Nebraska | | | | | Lincoln | 2023 | 2023 | Virtual airlne |
| Red Wing Flying Service | Massachusetts | | | | | Ware | 1929 | 1929 | Air taxi |
| Rediske Air | Alaska | | | | | Soldotna | 1991 | 2017 | |
| Redline Air Charters | Alaska | | | | | Ruby | 1996 | 2010 | |
| Reeve Aleutian Airways | Alaska | | RV | RVV | REEVE | Anchorage | 1932 | 2001 | |
| Regent Air | California | | | | | Los Angeles | 1983 | 1986 | Established as First Air. Operated Boeing 727 |
| Regina Cargo Airlines | Florida | | | | | Miami | 1948 | 1960 | Supplemental air carrier changed its name to Imperial Airlines in 1960 |
| RegionsAir | Tennessee | | 3C | CEA | CORP-X | Smyrna | 1996 | 2007 | |
| Reilly Air Service | California | | | | | Los Angeles | 1968 | 1971 | Operated Beech 18 |
| Reliant Airlines | Michigan | | | RLT | | | 1984 | 2002 | |
| Reno Air | Nevada | | QQ | ROA | RENO AIR | Reno–Tahoe | 1992 | 1999 | Merged into American Airlines |
| Reno Air Express | California | | | | | San Jose | 1994 | 1995 | |
| Renown Aviation | California | | RG | RGS | | Santa Maria | 1980 | 2000 | Established as Western Aircraft Salvage |
| Republic Airlines | Minnesota | | RC | REP | REPUBLIC | Minneapolis–Saint Paul | 1979 | 1986 | Merged into Northwest Airlines |
| Resort Air | Missouri | | | | | St. Louis Lambert | 1983 | 1989 | Renamed to Trans States Airlines. Operated Swearingen Metro |
| Resort Air | Rhode Island | | | | | Block Island | 1990s | 1990s | Charter carrier |
| Resort Air | Oregon | | | | | Sunriver | 1992 | 1992 | Scenic tours |
| Resort Airlines | North Carolina Florida District of Columbia | | RA | RA | | Pinehurst, North Carolina New York City Miami | 1945 | 1960 | Scheduled international carrier limited to "sky cruises" |
| Resort Airlines | Maryland | | | | | Baltimore–Washington | 1982 | 1986 | Operated Piper aircraft |
| Resort Airways | Hawaii | | | | | Honolulu | 1960 | 1971 | Absorbed by HATS Hawaiian Air Tour Service. Operated Aero Commander 500 |
| Resort Commuter | California | | | | | Orange County | 1988 | 1995 | Operated Convair 580 |
| Resort Commuter Airlines | South Carolina | | | | | | 1975 | 1979 | Renamed to Mid-South Airlines |
| Resort Commuter Airlines | California | | XK | | | Orange County | 1984 | 1989 | Established as Catalina Commuter |
| Rhoades International | Indiana | | | RDS | | Columbus | 1989 | 2006 | Renamed to Rhoades Aviation. Operated Convair C-131, Convair 240, DC-3, Douglas DC-6 |
| Rich International Airways | Florida | | JN | RIA | RICHAIR | Miami | 1970 | 1996 | |
| Richmond Aviation | Virginia | | | | | Richmond | 1963 | 1971 | Operated Piper Twin Comanche, Twin Bonanza, Mitsubishi MU-2 |
| Riddle Airlines | Florida | | | | | Miami | 1945 | 1965 | Rebranded as Airlift International |
| Rio Airways | Texas | | XO | REO | RIO | Skylark Field | 1967 | 1986 | Began as Hood Airlines |
| Rio Grande Air | | | | | | | 1999 | 2003 | Cessna Caravan operator |
| RKO General | Massachusetts | | | | | | 1968 | 1970 | Helicopter air taxi. Operated Bell 47, Bell 206 |
| Robertson Aircraft Corporation | Missouri | | | | | Lambert Field | 1925 | 1929 | |
| Robin Airlines | California | | | | | Long Beach | 1950 | 1951 | Renamed to North Continent Airlines |
| Robinson Airlines | New York | | | | | Ithaca | 1945 | 1952 | Renamed to Mohawk Airlines |
| Roblex Aviation | Puerto Rico | | | ROX | | San Juan | 1997 | 2013 | Cargo operator |
| Rochester Aviation | Minnesota | | | | | Rochester | 1969 | 1971 | Operated Cessna 206 |
| Rockford Air Charter | Illinois | | | | | Chicago Rockford | 1964 | 1971 | Operated Cessna 206, Beech 18, Piper Twin Comanche |
| Rocky Mountain Airways | Colorado | | JC | RMA | ROCKY MOUNTAIN | Denver Stapleton | 1965 | 1991 | Began as Vail Airways. Merged into Continental Express |
| Rogers Heavy Lift Helicopters | California | | | | | Fresno Yosemite | 1994 | 1998 | Operated Sikorsky CH-54 Tarhe |
| Roscoe Turner Aeronautical Corporation | Georgia | | | | | Candler Field | 1925 | 1928 | Operated Sikorsky S-29-A |
| Rose Aviation | California | | | | | Hawthorne | 1968 | 1969 | Operated Piper Apache, Aero Commander 500 |
| Rosenbalm Aviation | Michigan Oregon | | 9R | RAX | ROSIE | Willow Run | 1960 | 1991 | DC-8 contract flyer for Emery & Burlington. Became Flagship Express Services |
| Roseswift Air Service | Michigan | | | | | Grand Rapids | 1920 | 1920 | Founded by Arthur Rosenthal and Thomas Swift. Operated Curtiss Jenny |
| Roswell Airlines | New Mexico | | | | | Roswell | 1976 | 1981 | Founded by Dick Callens. Operated Piper Seneca |
| Roust Airways | Alaska | | | | | Nome | 1930 | 1935 | Founded by Thomas Pedersen Roust |
| Royal Air | Missouri | | | | | Kansas City | 1978 | 1980 | Operated Embraer Bandeirante |
| Royal American Airlines | Arizona | | | | | Tucson | 1977 | 1986 | Operated Vickers Viscount |
| Royal American Airways | | | | RLM | | | 1981 | 1993 | Operated Convair 240, Convair 600, Vickers Viscount |
| Royal Hawaiian Air Service | Hawaii | | ZH | | | | 1971 | 1986 | Established as Hawaii Wings in 1963. Operated Cessna 402C |
| Royal Hawaiian Airlines | Hawaii | | | | | Honolulu | 1985 | 1986 | |
| Royal West Airlines | Nevada | | | | | Las Vegas McCarran | 1981 | 1982 | Operated DC-3 |
| Royal West Airlines | Colorado | | | RWE | ROYAL WEST | Colorado Springs | 1981 | 1987 | Merged with Aero West Airlines in 1982. Operated DC-3, BAe 146 |
| Royal West Airlines | Nevada | | | | | Las Vegas McCarran | 1986 | 1987 | |
| Royal-Air | Arkansas | | | | | Goodwin Field | 1982 | 1982 | Established as Jamaire. Renamed to Sunbelt Airlines |
| Royale Airlines | Louisiana | | OQ | RAY | ROYALE AIR | New Orleans Armstrong | 1968 | 1989 | |
| Rugby Aviation | Washington | | | | | Seattle-Tacoma | 2002 | 2007 | Renamed to Northwest Sky Ferry |
| Russia Jet Direct | Washington | | RD | RYN | | Seattle–Tacoma | 2005 | 2005 | |
| Ryan Air | Alaska | | | | | Anchorage | 1979 | 1988 | Established as Unalakleet Air Taxi. Renamed to Arctic Transportation Services |
| Ryan Airline Company | California | | | | | San Diego | 1925 | 1926 | |
| Ryan Aviation | Kansas | | | RYN | | Wichita | 1977 | 1988 | previously DeBoer Aviation; became PHH Air |
| Ryan International Airlines | Illinois Kansas | | RD | RYN | RYAN INTERNATIONAL | Chicago Rockford Wichita | 1989 | 2013 | previously PHH Air and before that, Ryan Aviation |
| S |
| S.I. Airways | Texas | | | | | Amarillo | 1974 | 1975 | |
| S.S. Airways | Kansas | | | | | Amarillo | 1972 | 1972 | Renamed to Century Airlines |
| S.S.W. | Texas | | | | | El Paso | | 1959 | Supplemental air carrier shut by CAB in 1959 for stranding passengers due to lack of funds. dba Universal Airlines 1957–1959 |
| Saber Aviation | | | SP | SBR | | | 1978 | 1991 | |
| Safeway Airlines | Alaska | | | | | Fairbanks | 1964 | 1968 | Operated Piper Apache, Piper Comanche, Cherokee Six |
| Sair | New York | | | | | Syracuse | 1961 | 1999 | |
| Salair | Alaska | | 8S | SIR | | Anchorage | 1980 | 1997 | Operated DC-3, Convair 440. Renamed to Air Alaska Cargo |
| Salmon Air | Idaho | | S6 | MBI | | Boise | 1968 | 2009 | Merged into McCall Aviation |
| Samoa Air | American Samoa | | | | | Pago Pago | 1987 | 2003 | |
| Samoan Airlines | American Samoa | | SX | SX | | Pago Pago | 1959 | 1960 | CAB-certificated as an intl carrier. |
| San Diego Sky Freight | California | | | | | San Diego | 1950 | 1952 | Cargo operator |
| San Francisco and Oakland Helicopter Airlines | California | | OH | | SFO AIRLINES | San Francisco | 1961 | 1986 | |
| San Juan Airlines | Washington | | | | | Port Angeles | 1947 | 1989 | Commuter operator |
| San Juan Airlines | | | YS | | | | 1970 | 1989 | Merged into Alaska Airlines |
| San Marino Taxi Aereo | California | | | | | Long Beach | 1999 | 2003 | |
| Santa Fe Airline Company | New Mexico | | | | | Santa Fe | 1972 | 1972 | Intrastate air carrier |
| Santa Fe Skyway | | | | | | | 1946 | 1947 | |
| Santa Maria Airlines | California | | | | | Hancock Field | 1928 | 1935 | Founded by George Allan Hancock |
| SAT-Air | Texas | | | | | San Antonio | 1983 | 1995 | Renamed to Merlin Express |
| Satellite Aero | Wyoming | | | | | Jackson Hole | 1990 | 1995 | Operated Cessna 206, Cessna 402C, Piper Navajo |
| Saturn Airways | California | | KS | | | Oakland | 1960 | 1976 | All American Airways until 1960. Supplemental air carrier. Merged into Trans International Airlines |
| Sawyer Aviation | Arizona | | | | | Phoenix Sky Harbor | 1961 | 1998 | Operated Cessna 182, Cessna 425C, Cessna Citation |
| SB Air | Texas | | | | | Dallas Love Field | 1999 | 2019 | Established as Seven Bar Flying Services. Renamed to SevenBar Aviation. Medical transport operator. |
| Scanderbeg Air | New York | | P1 | | | New York Kennedy | 2009 | 2009 | Charter carrier |
| SCAT South Central Air Transport | Arkansas | | | | | Fayetteville | 1946 | 1948 | Operated Cessna UC-78 |
| Scenic Air | California | | | | | Columbia | 1994 | 1995 | |
| Scenic Air Tours Hawaii | Hawaii | | | | | Honolulu | 1992 | 1996 | |
| Scenic Airlines | Nevada | | YR | YRR | | North Las Vegas | 1967 | 2007 | Acquired by Grand Canyon Airlines and renamed to Grand Canyon Scenic Airlines |
| Scenic Airways | Arizona | | | | | Grand Canyon | 1927 | 1930 | Renamed to Grand Canyon Airlines |
| Scheduled Skyways | Arkansas | | | | | Fayetteville | 1953 | 1972 | Merged into Air Midwest |
| Scheerer Air | Florida | | | | | Palm Beach | 1979 | 1980 | Merged into Florida Commuter Airlines |
| Seaboard & Western Airlines | New York | | | | | New York Kennedy | 1947 | 1961 | Renamed to Seaboard World Airlines |
| Seaboard World Airlines | New York | | SB | SEW | SEABOARD | New York Kennedy | 1946 | 1980 | As Seaboard & Western Airlines, merged into Flying Tiger Line |
| Seaco Airlines | Michigan | | | | | Detroit Metro | 1976 | 1980 | Operated Cessna 402, Piper Aztec |
| Seacoast Air Transport | Massachusetts | | | | | New Bedford | 1937 | 1939 | |
| SeaCoast Airlines | Florida | | | SCC | SEA-COASTER | St. Pete–Clearwater | 2002 | 2012 | |
| Seagull Air | Alaska | | | | | Bethel | 1988 | 1989 | Founded by J. Timothy Cracie |
| Seagull Air Lines | Utah | | | | | Salt Lake City | 1929 | 1930 | Operated Curtiss Robin |
| Seair Alaska Airlines | Alaska | | | | | Anchorage | 1980 | 1986 | Established as Sea Airmotive. Operated Convair 440, Twin Otter |
| Seaplanes of Key West | Florida | | | | | Key West | 2004 | 2006 | |
| SeaPort Airlines | Oregon | | K5 | SQH | SASQUATCH | Portland | 2008 | 2016 | Went into bankruptcy |
| Seattle Air Charter | Washington | | | | | Seattle-Tacoma | 1947 | 1949 | |
| Seattle Commuter Airlines | Washington | | | | | Seattle-Tacoma | 1965 | 1968 | Scheduled commuter air services |
| Seattle Flying Services | Washington | | | | | Seattle | 1930 | 1930 | Founded by Vern Gorst |
| Seattle-Victoria Airmail Line | Washington | | | | | Seattle | 1919 | 1919 | Established as Hubbard Air Transport |
| Sentinel Airlines | Texas | | | | | Abilene | 1971 | 1971 | Operated Cessna 402 |
| Seven Bar Flying Services | Texas | | | | | Dallas Love Field | 1947 | 1999 | Medical transport operator. Renamed SB Air |
| Seven Seas Airlines | California | | | | | Burbank | 1957 | 1961 | Operated C-46, DC-4 |
| Severson Air Activities | Montana | | | | | Great Falls | 1964 | 1971 | Operated Cessna 182, Cessna 320 |
| Seward Airways | Alaska | | | | | Seward | 1937 | 1939 | Founded by John Littley |
| Shalkow Air Cargo Express | Ohio | | | | | Cleveland Hopkins | 1982 | 1989 | Established as Ace Air Cargo Express. Operated C-47 |
| Shasta Air | California | | | | | Yreka Rohrer Field | 1968 | 1983 | Operated Piper Navajo |
| Shavano Air | Colorado | | | SHV | SHAVANO | Harriet Alexander Field | 1960 | 2002 | |
| Shawnee Airlines | Florida | | XW | SHW | SHAWNEE | Orlando Executive | 1968 | 1975 | Acquired by Florida Airlines |
| Shawnee Airways | Ohio | | | | | Akron–Canton | 1961 | 1972 | Founded by Ernest Stadvec |
| Sheffield P. Wilds | South Carolina | | | | | | 1967 | 1971 | Operated Aero Commander 500, Piper Apache |
| Shelby Sky Haven | Ohio | | | | | Mansfield | 1948 | 1963 | Renamed to GCS Air Service |
| Shelter Charter Services | Georgia | | | | | Atlanta | 2017 | 2017 | Operated Cessna Citation I |
| Shelton-Jefferson Airways | Missouri | | | | | St. Louis Lambert | 1930 | 1931 | Operated Ogden Osprey |
| Shenandoah Airlines | Virginia | | | | | Charlottesville–Albemarle | 1968 | 1970 | Operated Beech E18S |
| Shoreline Aviation | Connecticut | | | | | Tweed New Haven | 1980 | 2020 | Operated Cessna Caravan seaplane |
| Shorter Airlines | Michigan | | | | | Pellston Regional | 1968 | 1975 | Operated Beech E18S, DC-3 |
| Shuttle Air Lines | California | | | | | Glendale Grand Central | 1931 | 1932 | Operated Ogden Osprey |
| Shuttle America | Indiana | | S5 | TCF | MERCURY | Chicago O'Hare | 1995 | 2017 | Republic Airways Holdings merged into another subsidiary |
| Shuttle by United | California | | UA | UAL | UNITED | San Francisco | 1994 | 2001 | Subsidiary of United Airlines, renamed United Shuttle |
| Sidles Airways | Nebraska | | | | | Lincoln | 1930 | n/a | Operated Stinson Detroiter (NC7474) |
| Siemans Air Transport | Pennsylvania | | | | | Uniontown | 1927 | n/a | Founded by Charles L. Siemans |
| Sierra Expressway | California | | | SRX | SIERRA EX | Oakland | 1994 | 1996 | |
| Sierra Mountain Airways | California | | | | | Oakland | 1987 | 1989 | |
| Sierra Nevada Airways | Nevada | | ZS | | | Las Vegas McCarran | 1984 | 1997 | Operated Beech Baron, Cessna 402C |
| Sierra Pacific Airlines | California | | | | | Oakland | 1965 | 1966 | Operated Beech 18 |
| Sierra Pacific Airlines | Arizona | | | | | Tucson | 1976 | 1982 | |
| Sierra West Airlines | California | | | | | Van Nuys | 1974 | 1975 | Operated Beech Queen Air |
| Silver State Airlines | Nevada | | | | | Las Vegas McCarran | 1979 | 1982 | Charter carrier |
| Silver State Helicopters | Nevada | | | | | Henderson Executive | 1999 | 2008 | |
| Silver Wings Aviation | South Dakota | | | | | Rapid City | 1975 | 1976 | |
| Silver Airways | Florida | | | | SILVER | Tampa | 2011 | 2025 | |
|
| Simmons Airlines | Michigan | | MQ | SYM | SIMMONS | Marquette | 1978 | 1998 | Merged into American Eagle Airlines |
| Sis-Q Flying Service | California | | | | | Sonoma County | 1962 | 1979 | Aerial fire fighting. Operated Grumman Tigercat |
| Sisk Aviation Activities | Illinois | | | | | St. Louis Downtown | 1964 | 1977 | Third-level services |
| Sizer Airways | North Dakota | | | | | Fargo-Hector Field | 1970 | 1979 | Established as Luthi Aviation. Operated Beech 18, Riley Rocket |
| Skagway Air Service | Alaska | | 7J | SGY | | | 1964 | 2007 | |
| Sky Bus Public Charter | Florida | | | | | Fort Lauderdale | 1993 | 1993 | Operated Boeing 727-200 |
| Sky Courier | | | | | | | 1988 | 1988 | To Airborne Express |
| Sky Harbor Air Service | Nebraska | | NE | SKD | SKY DAWG | Omaha | 1954 | 1970 | |
| Sky Harbor Air Services | Wyoming | | WY | SHC | SKY HARBOR CHEYENNE | Cheyenne | 1988 | | |
| Sky King | Florida | | 5K | SGB | SONGBIRD | Miami | 1990 | 2015 | Rebranded as Songbird Airways |
| Sky Tours | Massachusetts | | | | | | 1947 | 1953 | Established as Erie Isle Airways. Renamed to Island Airlines |
| Sky Tours Hawaii | Hawaii | | | | | | 1965 | 1971 | |
| Sky Trek International Air Lines | Virginia | | | | | Richmond | 1996 | 2000 | Renamed Discovery Airways in 1999 |
| Sky Trucks International | Florida | | | | | Fort Lauderdale | 1972 | 1975 | |
| Skybus Airlines | Ohio | | SX | SKB | SKYBUS | Columbus | 2007 | 2008 | |
| Skybus Express | Georgia | | | | | Atlanta | 1991 | 1992 | Operated GAF Nomad |
| Skycoach | California | | | | | | | | 1950s combine. Aircraft in picture is Monarch Air Service or Currey Air Transport |
| Skyfreighters | Texas | | | | | Grand Prairie | 1984 | 1991 | Established as Coker Airfreight. Acquired by Kitty Hawk Airways. Operated Douglas C-117D |
| Skyfreight Airlines | Florida | | | | | Miami | 1981 | 1984 | Operated DC-3 |
| Skyline Air Service | Washington | | | | | Seattle-Tacoma | 1967 | 1969 | Founded by Tom Wilson. To Puget Sound Airlines |
| Skyline Motors Aviation Services | Ohio | | | | | Youngstown–Warren | 1979 | 1981 | Renamed to B.A.S Airlines |
| Skylink Airways | Maryland | | | | | Washington Dulles | 2003 | 2005 | Rebranded as MAXjet Airways |
| Skymark Airlines | California | | | | | Sacramento Executive | 1968 | 1969 | |
| Skymaster Air Taxi | New Hampshire | | 8M | SDD | SKY DANCE | Laconia | 1989 | 1993 | Renamed Atlantic North Airlines |
| Skyservice USA | Colorado | | | | | Chicago Rockford | 1998 | 2000 | |
| Skystar International | Virginia | | | SSK | | Washington National | 1984 | 1987 | International pilgrimage |
| Skystream Airlines | Illinois | | DN | | | Chicago Meigs Field | 1973 | 1980 | Founded by Cecil Pond. Acquired Hub Airlines |
| SkyValue | Florida | | XP | CXP | RUBY MOUNTAIN | Fort Lauderdale-Hollywood | 2006 | 2007 | |
| SkyValue Airways | Michigan | | 4A | DYN | | Oakland County | 2018 | 2018 | |
| Skyvan Airways | | | | | | | 1963 | 1964 | Operated C-46 |
| Skyway Airlines (Skyway Aviation) | Missouri | | ZY | | | Forney Field | 1960 | 1979 | Air taxi operator |
| Skyway Airlines | | | | | | | 1968 | 1980 | Known as Skyway Commuter. Operated Beech E18S |
| Skyway Airlines | Wisconsin | | AL | SYX | SKYWAY-EX | Milwaukee Mitchell | 1994 | 2008 | |
| Skyway Commuter | Florida | | | | | Ocala | 1984 | 1985 | Established ad Skyway of Ocala |
| Skyway of Ocala | Florida | | | | | Ocala | 1981 | 1984 | Operated as Air Florida Commuter |
| Skyways International | Florida | | | | | Miami | 1946 | 1951 | Operated C-46, DC-3, Lockheed Lodestar |
| Skyways International | Florida | | | | | Miami | 1969 | 1972 | Renamed to Transair Cargo |
| Skyways International | Texas | | | | | Houston Bush | 1978 | | |
| Skyworld Airlines | Colorado | | PC | SPC | | Denver | 1986 | 1992 | Formerly Denver Ports of Call |
| Slick Airways | Texas | | SL | SL | | Hollywood Burbank | 1946 | 1966 | To Airlift International |
| Slocum Airlines | Florida | | | SLO | SLOCUM | Miami | 1981 | 1984 | Operated as Air Florida Commuter |
| Small Community Airlines | Florida | | | | | Dallas Love Field | 2007 | 2009 | Operated BAE Jetstream |
| SMB Stage Lines | Texas | | MJ | STG | STAGE | Dallas Fort Worth | 1967 | 1990 | Operated Convair 580, Convair 600, DC-3 |
| Smokers Express | Florida | | | | | Melbourne Orlando | 1993 | 1993 | Not launched |
| Smyer Aircraft | Kansas | | | | | Strother Field | 1968 | 1972 | Operated Cessna 206, Cherokee Six |
| Solar Airlines | New Mexico | | | | | Roswell | 1964 | 1971 | Operated Beech 18, Dumod Infinité I, PacAero Tradewind |
| Soldotna Air Service | Alaska | | | | | Soldotna | 1978 | 1979 | |
| Song | Georgia | | DL | DAL | DELTA | Atlanta | 2003 | 2006 | Merged back in with its parent company, Delta Air Lines |
| Songbird Airways | Florida | | 6K | SGB | SONGBIRD | Orlando | 1990 | 2017 | Began as Sky King Inc. |
| Sonora Air Lines | Nevada | | | | | Reno–Tahoe | 1967 | 1971 | Operated Cessna 150, Cessna 172, Piper PA-23 |
| Sourdough Air Transport | Alaska | | | | | Fairbanks | 1953 | 1962 | |
| South Atlantic Airlines | South Carolina | | | | | Myrtle Beach | 1968 | 1969 | Operated Aero Commander 500, Turbo Commander 690 |
| South Bend Airways | Indiana | | | | | Cadet Field | 1927 | n/a | Founded by Stephen Darius, Carl G Jordan. Operated Pheasant H-10 |
| South Central Air | Alaska | | | SCA | | Kenai | 1967 | 2001 | Founded by Harold and Irene Andersen. Operated BAe Jetstream 31, BN Islander, Cessna |
| South Central Air Transport (SCAT) | Mississippi | | | | | Natchez–Adams | 1971 | 1977 | |
| South Central Airlines | Florida | | | | | Ocala | 1963 | 1964 | |
| South East Airlines | | | | | | | | | The name of a 1950s combine, in whose name associated carriers flew. |
| South Pacific Air Lines | California | | | | | Honolulu | 1960 | 1963 | Merged into Pan Am in 1964 |
| South Pacific Island Airways | Hawaii | | HK | SPI | SOUTH PACIFIC | Honolulu | 1973 | 1987 | |
| South Winds Cargo | Florida | | WE | SWC | | Miami | 2002 | 2005 | Merged into Centurion Cargo. Operated DC-10 |
| Southcentral Air | Alaska | | XE | SCA | SOUTH CENTRAL | Kenai | 1975 | 1999 | |
| Southeast Airlines | Tennessee | | SL | | SOUTHEAST | Tri-Cities | 1956 | 1959 | |
| Southeast Airlines | Florida | | NS | SEA | SOUTHEAST AIR | Miami | 1966 | 1981 | Originally known as Cat Cay Airlines |
| Southeast Airlines | Florida | | Sl | SNK | | Youngstown–Warren | 1999 | 2004 | |
| Southeast Airlines (Southeastern Aviation) | Tennessee | | | | | Jackson | 1960 | 1979 | Operated de Havilland Dove |
| Southeast Skyways | Alaska | | SE | | | Juneau | 1968 | 1983 | Founded by Dean Williams and Billy Bernhardt. Operated Cessna 207, DHC Beaver |
| Southeastern Commuter Airlines | Georgia | | | | | Atlanta | 1973 | 1983 | Acquired by Atlantic Southeast Airlines |
| Southern Air Transport (1929) | Texas | | | | | | 1929 | 1929 | Controlled by Avco, the company that organized American Airlines |
| Southern Air Transport | Florida Ohio | | SJ | SJM | SOUTHERN AIR | Miami Columbus, Ohio | 1947 | 1998 | CIA-owned 1960–1973. Assets became Southern Air |
| Southern Airlines | Florida | | | | | | 1981 | 1981 | Rebranding Florida Commuter Airlines |
| Southern Airlink | Mississippi | | | | | Bay Springs | 1996 | 1997 | |
| Southern Airways | Georgia | | SO | SO | SOUTHERN | Atlanta | 1949 | 1979 | Merged with North Central Airlines to form Republic Airlines (1979–1986) |
| Southern Airways | Mississippi | | | | | Jackson–Medgar | 1985 | 1987 | Established a Flight Line |
| Southern Aviation | Oklahoma | | | | | Lawton | 1964 | 1974 | Operated Cessna 182, Cessna 206 |
| Southern Cross Airways | | | | | | | 1959 | 1960 | Operated C-46 |
| Southern Express | Florida | | | | | | 1984 | 1986 | Formerly known as Finair Express |
| Southern International Airways | Florida | | | | | | 1981 | 1981 | Successor of Florida Airlines operated as Air Florida Commuter |
| Southern Jersey Airways | New Jersey | | 6J | ALC | ACOM | Cape May | 1946 | 1991 | Established as Atlantic City Airlines operating as Allegheny Commuter |
| Southern Jersey Resorts Airways | New Jersey | | | | | Atlantic City | 1965 | 1990 | Operated Twin Otter, Dash-8 |
| Southern Maryland Aviation | Maryland | | SF | | | St. Mary's County | 1977 | 1979 | |
| Southern Nevada Airlines | Nevada | | | | | | 1980 | 1981 | |
| Southern Skyways | Georgia | | | | | Atlanta | 1980 | | A virtual airline (economics) which markets air travel branding |
| Southwest Air Fast Express | Oklahoma | | | | | St. Louis Lambert | 1928 | 1929 | Acquired by American Airlines |
| Southwest Airlines | Texas | | | | | San Antonio | 1965 | 1967 | Established as Wild Goose Flying Service |
| Southwest Airways | California | | | | | San Francisco | 1941 | 1958 | Local service carrier renamed to Pacific Air Lines |
| Southwest Ryan Airlines | Indiana | | | | | McIntyre Field | 1928 | n/a | Operated Ryan Brougham |
| Special Aviation Systems | Michigan | | | | | | 2001 | 2004 | Cargo carrier. Operated Embraer Bandeirante |
| Speed Star Express | California | | | | | | 1968 | 2005 | Operated Twin Otter |
| Spirit Air | Alaska | | | | | | 2005 | 2009 | Commuter and package carrier |
| Spirit Aviation | California | | | | | Van Nuys | 1994 | 1995 | Charter operator |
| Spirit Lake Airways | Iowa | | | | | Spencer | 1977 | 1979 | Renamed to Great Lakes Airlines |
| Spirit of America Airlines | California | | IM | IAS | BOXHALUER | Los Angeles | 1959 | 1989 | Established as IASCO |
| Spokane Airways | Washington | | | | | Spokane | 1990 | 2012 | |
| Sports Air Travel | Oregon | | | WCC | WEST COAST | Portland–Troutdale | 1982 | 1999 | |
| Sports Air Travel | California | | | | | Burbank | 1997 | 1997 | To Ameriflight |
| Sports by Air | South Carolina | | | | | Hilton Head | 1968 | 1971 | Operated Aero Commander 680 |
| Sportsflight Airways | Arizona | | | | | Tucson | 1993 | 1995 | Renamed to Pacific International Airlines |
| St. Germain Aviation | Illinois | | | | | Meigs Field | 1964 | 1971 | Operated Piper Twin Comanche |
| St. Petersburg–Tampa Airboat Line | Florida | | | | | St. Petersburg | January 1914 | May 1914 | Benoist Type XIV |
| Stadvec Aviation | Illinois | | | | | Akron–Canton | 1958 | 1961 | Founded by Ernest Stadvec. Operated Piper PA-22 Tri-Pacer |
| Stagecoach Airways | Texas | | | | | San Antonio | 1958 | 1961 | Operated Beech Twin Bonanza, Lockheed L.12 Electra |
| Standard Air Cargo | California | | | | | San Diego | 1946 | 1953 | Original name of Standard Airways |
| Standard Air Lines | California | | | | | Los Angeles | 1927 | 1930 | Subsidiary of Aero Corporation of California. In 1930 acquired by Western Air Express |
| Standard Air Lines | California | | | | | Long Beach | 1945 | 1949 | Established as Fireball Air Express |
| Standard Airways | California | | FD | | | San Diego Burbank | 1946 | 1969 | Established as Standard Air Cargo |
| Standard Airways | Michigan | | | | | Pontiac | 1966 | 1969 | Operated Beech 18, Piper Navajo |
| Star Air Service | Alaska | | | | | Anchorage | 1932 | 1944 | Renamed to Alaska Airlines |
| Starflight | Nevada | | | | | Reno–Tahoe | 1975 | 1975 | Operated BAC One-Eleven |
| Starlight Express | | | | | | | 1987 | 1991 | Cargo feeder for FedEx Express |
| Starflite | New York | | | | | White Plains | 1965 | 1966 | Contract service operator |
| Starship Airlines | Arizona | | | | | Tucson | 1991 | 2000 | Operated Convair 240C, Convair 440F |
| Starstruck Jet | Tennessee | | | | | Nashville | 1998 | 1998 | |
| State Airlines | South Carolina | | | | | Charlotte Douglas | 1940 | 1940 | Operated Lockheed Lodestar, Bellanca Cruisair |
| State Airlines | Florida | | | | | Ft. Lauderdale | 1981 | 1984 | |
| StatesWest Airlines | Arizona | | YW | SWJ | STATES | Phoenix Sky Harbor | 1986 | 1993 | |
| Stateswide Airline | New Hampshire | | | | | Manchester–Boston | 1964 | 1965 | Operated de Havilland Dove |
| Stearns Air Alaska | Alaska | | | | | Anchorage | 1992 | 2001 | |
| Stewart Air Service | California | | | | | Los Angeles | 1946 | 1971 | |
| Stol Air Commuter | California | | VB | | | Fresno Yosemite | 1972 | 1978 | Renamed WestAir Commuter Airlines |
| Stout Air Services | Michigan | | | | | Ford Airport | 1925 | 1930 | Purchased by National Air Transport |
| Strachan Skyways | Georgia | | | | | Hunter Field | 1936 | 1938 | |
| Streamline Air | Massachusetts | | | SRY | STINGRAY | Hanscom Field | 2010 | 2012 | |
| Suburban Airlines | | | AL | | | DuBois | 1968 | 1989 | To Allegheny Airlines |
| Suburban Airways | California | | | | | | | | |
| Summit Airlines | Pennsylvania | | DU | SMM | SUMMITAIR | Philadelphia | 1966 | 1986 | Established as Del Air Cargo Airlines |
| Summit Airways | Colorado | | | | | Denver | 1946 | 1947 | Established as Challenger Airlines |
| Summit Aviation | Florida | | | | | Miami | 1999 | 1999 | Charter operator |
| Sumo Airlines | New York | | SM | | | New York Kennedy | 1988 | 1996 | Cargo operator. Operated Piper Lance |
| Sun Air Express | Florida | | | | | Fort Lauderdale | 2014 | 2016 | Acquired by Southern Airways Express |
| Sun Air International | Florida | | | | | Fort Lauderdale-Hollywood | 2011 | 2014 | Rebranded as Sun Air Express |
| Sun Aire Lines | California | | OO | | | Palm Springs | 1968 | 1984 | Established as Borrego Springs Airlines. Merged into SkyWest Airlines |
| Sun Airlines | Missouri | | | | | St. Louis Lambert | 1967 | 1970 | Founded by George Caleshu. Operated Beech 18, Twin Otter, de Havilland Heron |
| Sun Airlines | Florida | | YX | | | | 1969 | 1978 | |
| Sun Jet International | Florida | | JX | SJI | SUNJET | St. Pete–Clearwater | 1993 | 1997 | Founded by Tom Kolfenbach. Renamed to Southeast Airlines |
| Sun Land Airlines | Nevada | | RF | | | Reno | 1980 | 1981 | Operated single Boeing 737-200 |
| Sun Pacific International | Arizona | | | SNP | | Tucson | 1995 | 1999 | Operated Boeing 727-200 |
| Sun Valley Airlines | Utah | | | | | Salt Lake City | 1964 | 1972 | Established as Janss Airways in 1964. Acquired by Key Airlines |
| Sun Valley Key Airlines | Idaho | | | | | Friedman Memorial | 1968 | 1972 | Formerly Sun Valley Airlines renamed to Key Airlines |
| Sun West Airlines | Arizona | | KY | SNW | SUN WEST | Phoenix Sky Harbor | 1980 | 1985 | |
| Sunaire Express | Virgin Islands | | OY | SUA | SUNBIRD | Saint Croix Rohlsen | 1982 | 1994 | Went bankrupt |
| Sunbelt Airlines | Arkansas | | JM | BTR | | Harrell Field | 1979 | 1984 | Known as Jamaire until March 1982 |
| Sunbird Air | Florida | | | | | Fort Lauderdale | 1984 | 1989 | Operated Convair 440 |
| Sunbird Airlines | North Carolina | | ED | SBD | SUNBIRD | Charlotte Douglas | 1979 | 1987 | Absorbed by Atlanta Express. Became CCAir in 1986. |
| Sunbird Airlines | Tennessee | | | | | Nashville | 1980 | 1980 | Operated Piper Cherokee Six |
| Sunbird Airways | Florida | | B6 | | | Orlando | 1993 | 1996 | |
| SunCoast Airlines | Florida | | WS | SNT | SUNCOAST | Fort Lauderdale-Hollywood | 1986 | 1988 | Went bankrupt. Operated Boeing 727-100 |
| Sunjet Aviation | Florida | | | | | Orlando Sanford | 1997 | 1999 | Operated Cessna Citation V, Learjet 35 |
| Sunship 1 Airlines | Illinois | | | | | Chicago Rockford | 2005 | 2005 | Trade name for Ryan International |
| Sunrise Airlines | Nevada | | OQ | SDC | SUNDANCE | Las Vegas McCarran | 1967 | 2000 | Established as Lake Powell Air Service |
| Sunwest International | | | | | | | | | |
| Sunworld International Airlines | Kentucky | | SM | SWI | SUNWORLD | Cincinnati/Northern Kentucky | 1996 | 2004 | |
| Sunworld International Airways | Nevada | | JK | SWI | SUNWORLD | Las Vegas McCarran | 1983 | 1988 | Established as Jetwest International Airways |
| Supair | California | | | | | Buchanan Field | 1950 | 1953 | Operated DC-3 |
| Superior Air | West Virginia | | | | | Fairmont | 1972 | 1973 | Operated BN Islander |
| Superior Airlines | Georgia | | | | | Atlanta | 1960 | 1963 | Operated de Havilland Dove, Aero Commander |
| Superior Airlines | Indiana | | | | | | 1961 | 1962 | |
| Superior Airlines | Arizona | | | | | Columbus Glenn | 1994 | 2003 | To Mesa Airlines |
| Susquehanna Airways | New York | | | | | Sidney | 1979 | 1985 | Established as Forde-Aire. Operated Riley Turbo Skyliner, Piper Aztec |
| Swift Air | Florida | | WQ | SWQ | SWIFTFLIGHT | Miami | 1997 | 2019 | Renamed to iAero Airways |
| Swift Aire Lines | California | | WI | | | San Luis Obispo | 1969 | 1981 | Merged with Golden Gate Airlines |
| Swissjets | Florida | | | | | Fort Lauderdale | 2000 | 2001 | Renamed to Tourjets |
| T |
| T & G Aviation | Arizona | | | | | Buckeye | 1990 | 2000 | Renamed to International Air Response. Operated Douglas DC-6, Douglas DC-7B |
| TAB Express Airlines | Florida | | | TBI | TAB | Melbourne Orlando | 1992 | 2005 | Operated Beech 1900 |
| TAG Airlines | Michigan | | | | | Detroit City | 1955 | 1970 | Shut down following crash |
| TAT-Maddux Air Lines | | | | | | | 1929 | 1930 | Merged with Western Air Express to form Transcontinental & Western Air |
| Tahoe Air | California | | XP | CXP | CASINO EXPRESS | Lake Tahoe | 1999 | 1999 | |
| Taku Glacier Air Gold | Alaska | | | | | Juneau | 1984 | 1994 | Operated Cessna Stationair, DHC Beaver |
| Talkeetna Air Service | Alaska | | | | | Talkeetna | 1947 | 1948 | Renamed to Talkeetna Air Taxi |
| Tamgass Aviation | Alaska | | | | | | 1964 | 1969 | Renamed to Southcoast Airways |
| Tanana Air Taxi | Alaska | | | | | Tanana | 1972 | 1974 | Renamed to Alaska Central Airways |
| Tanner Airlines | California | | | | | Los Angeles | 1930s | 1930s | Operated Stinson Detroiter |
| TapJets | North Dakota | | | | | Fargo Hector | 2016 | 2018 | |
| Taquan Air Service | Alaska | | | | | Ketchikan | 1977 | 2000 | Renamed to Taquan Air. Operated DHC Beaver |
| Tar Heel Aviation | North Dakota | | | THC | TARHEEL | Jacksonville Ellis | 1975 | 2000 | |
| Tatonduk Flying Service | Alaska | | | | | Eagle | 1977 | 1980 | Renamed to Everts Air Alaska. Operated Cessna 180 |
| Taxi Air Group | Ohio | | | | | Cleveland Burke Lakefront | 1955 | 1957 | Founded by William Knight. Renamed to TAG Airlines. Operated DHC Otter |
| Ted | Illinois | | UA | UAL | UNITED | Denver | 2004 | 2009 | Merged back into parent company United Airlines |
| Tejas Airlines | Texas | | TB | | | San Antonio | 1976 | 1980 | Filed for Chapter 11 bankruptcy |
| Telair International | | | | | | | | | |
| Telford Aviation | Maine | | | | | | 1995 | 2004 | |
| Tempelhof Airways | Florida | | | TEH | TEMPELHOF | Fort Lauderdale | 1981 | 1990 | Operated from West Berlin |
| Temple Airlines | | | | | | | 1968 | 1968 | |
| Tempus Jets | South Carolina | | | | | Greenville–Spartanburg | 2007 | 2018 | Executive jet charter. Went bankrupt |
| TEMSCO Airlines | Alaska | | | | | Ketchikan | 1986 | 1991 | The helicopter division continue to operate as TEMSCO Helicopters Inc. |
| Tennessee Airways | Tennessee | | ZN | TEN | TENNESSEE | Knoxville McGhee | 1978 | 1990 | Operated Embraer Bandeirante |
| TennesseeSkies | Tennessee | | | | | Nashville | 2009 | 2012 | A Pacific Wings subsidiary |
| Tepper Aviation | Florida | | | | | Crestview | 1987 | 2006 | |
| Texas International Airlines | Texas | | TI | TIA | TEXAS | Houston Intercontinental DFW Airport | 1969 | 1982 | Merged into Continental Airlines |
| Texas National Airlines | Texas | | | TXN | TEXAS NATIONAL | San Antonio | 1986 | 1988 | Established as Border Airlines |
| Texas Air Leasing Corporation | Texas | | | | | | 1984 | 1990 | Aircraft leasing firm |
| The Air-Oasis Co | California | | | | | Long Beach | 1963 | 1963 | Operated DC-3 |
| The Gulf Coast Airline | Louisiana | | | | | New Orleans | 1923 | 1932 | Renamed to Johnson Airways |
| The Hagerstown Commuter | Maryland | | | | | Hagerstown | 1962 | 1983 | Operated as an Allegheny Commuter |
| The Hawaii Express | Hawaii | | LP | HEA | | Los Angeles | 1982 | 1983 | |
| The Lord's Airline | Florida | | 5Q | | | Miami | 1986 | 1987 | |
| The Maui Commuter | Hawaii | | | | | Kahului | 1975 | 1978 | Founded by Jack Holzman and Robert Frost. Established as Ananda Air |
| Thompson Aeronautical Corporation | Ohio | | | | | Cleveland | 1928 | 1932 | Renamed to Transamerican Airlines |
| Thor Solberg Aviation | New York | | | | | Curtiss Field | 1929 | 1930 | Operated Great Lakes 2-T-1, Bellanca CH-200 |
| Thunderbird Airlines | Utah | | | | | Ogden-Hinckley | 1964 | 1969 | Renamed to Key Airlines. Operated Twin Otter |
| Tibben Flight Lines | Iowa | | | | | Cedar Rapids | 1992 | 1996 | Charter operator |
| TMA Trans-Michigan Airlines | Michigan | | | | | Traverse City | 1969 | 1972 | Cargo carrier |
| TMC Airlines | Michigan | | | TMM | WILLOW RUN | Willow Run | 1994 | 2005 | Cargo carrier. Operated L-188, DC-8 |
| Tol Air | Puerto Rico | | TI | TOL | TOL AIR | | 1983 | 2006 | Acquired by Four Star Air Cargo |
| Tourjets | Florida | | | | | Fort Lauderdale | 2001 | 2002 | Established as Swissjets |
| Tower Air | New York | | FF | TOW | TEE AIR | New York Kennedy | 1983 | 2000 | |
| TPA-The Aloha Airline | Hawaii | | | | | Honolulu | 1950 | 1958 | Established as Trans-Pacific Airlines |
| TPI International Airways | Georgia | | UF | | | Brunswick Golden Isles | 1989 | 1996 | |
| Tradewinds Airlines | North Carolina | | WI | TDX | TRADEWINDS EXPRESS | Piedmont Triad | 1991 | 2010 | |
| Trans Air | Florida | | GO | TRA | TRANS ISLAND | Fort Lauderdale–Hollywood | 1982 | 1986 | Established as Trans Island Airways |
| Trans Air Lines | Louisiana | | | | | New Orleans Armstrong | 1962 | 1963 | Renamed to Air Lines. Operated Aero Commanders |
| Trans Air Link | Florida | | | | | Miami | 1986 | 1989 | |
| Trans Alaskan Airlines | Alaska | | | | | Anchorage | 1955 | 1963 | Operated DC-4, DC-6A, PBY-5A Catalina |
| Trans American Airways | California | | | | | Lockheed Air Terminal | 1946 | 1957 | Founded by Edward Ware Tabor. Member airline of North American Airlines Group |
| Trans American Charter | Illinois | | | ECQ | | Chicago O'Hare | 1992 | 1995 | |
| Trans Caribbean Airways | New York | | TR | TCA | | | 1945 | 1971 | Acquired by American Airlines |
| Trans Caribbean Air Cargo Lines | New York | | TR | TCA | | | 1945 | 1971 | Original name of Trans Caribbean Airways |
| Trans Continental Airlines | Michigan | | TD | TCN | TRANSCOM | Willow Run | 1974 | 1992 | Established as International Airlines Academy. Rebranded as Express.Net Airlines |
| Trans East Airlines | New Hampshire | | | | | Manchester–Boston | 1963 | 1972 | Formed as Statewide Airlines |
| Trans East International | New York | | | | | Farmingdale | 1982 | 1984 | Established as New York Air. Renamed to Island Air. Operated Twin Otter, Embraer Bandeirante |
| Trans Global Airlines | California | | | | | Long Beach | 1957 | 1961 | Founded by Donald Rich |
| Trans Global Airlines | New Jersey | | | | | Newark Liberty | 1979 | 1984 | Charter carrier |
| Trans Global Vacations | | | | | | | 2002 | 2003 | |
| Trans International Airlines | California | | TV | TV | TRANS INTERNATIONAL | Oakland | 1960 | 1979 | Supplemental air carrier, formed in 1946 as Los Angeles Air Service, rebranded to Transamerica Airlines in 1979 |
| Trans International Airlines | Florida | | LP | | | Orlando | 1985 | 1989 | reconstituted Central American International |
| Trans International Express | | | | BAP | BIG APPLE | | 1998 | 2002 | |
| Trans Island Airways | Florida | | GO | TRA | TRANS ISLAND | Fort Lauderdale–Hollywood | 1977 | 1982 | Sold and renamed to Trans Air |
| Trans Magic Airlines | Idaho | | | | | Boise | 1969 | 1974 | Merged into Air Idaho |
| Trans National Airlines | | | | | | | 1948 | 1957 | Originally Alaska Southern Airlines. Member airline of North American Airlines Group |
| Trans National Airlines (1973) | California | | | | | Oakland | 1973 | 1979 | |
| Trans Ocean Airways | Florida | | | | | Arcadia | 1989 | 1990 | Established as Gulf Air International |
| Trans Penn Airlines | Pennsylvania | | | | | Reedsville | 1971 | 1980 | Operated Piper Navajo |
| Trans Regional Airlines | Texas | | | | | Big Spring | 1975 | 1977 | Founded by Louis Rosembaum. Established as El Paso Transport |
| Trans Sierra Airlines | Arizona | | | TSI | | Tucson | 1970 | 1971 | Founded by Chris Condon and Allan Silliphant. Renamed to Sierra Pacific Airlines |
| Trans Southern Airways | South Carolina | | | | | Florence | 1976 | 1985 | Established as Pee Dee Air Express Inc. |
| Trans Southern Aieways | Georgia | | | | | | 1984 | 1985 | Routes that had been dropped by Piedmont Airlines |
| Trans States Airlines | Missouri | | AX | LOF | WATERSKI | Chicago–O'Hare Denver | 1989 | 2020 | Shutdown due to travel disruptions caused by the COVID-19 pandemic |
| Trans Tropic Airlines | Florida | | | | | Miami | | | |
| Trans World Airlines | Missouri | | TW | TWA | TWA | New York Kennedy | 1950 | 2001 | Merged into American Airlines |
| Trans World Connection | | | New York Kennedy Los Angeles | | |
| Trans World Express | | RZ | Philadelphia Northeast | 1987 | 1995 | |
| Trans-Air-Link | Florida | | | GJB | SKY TRUCK | Opa Locka | 1977 | ? | |
| Trans-Cal Airlines | California | | | | | Long Beach | 1968 | 1971 | Operated Beech Queen Air, Beech Bonanza |
| Trans-Central Airlines | Oklahoma | | ZM | ACN | | Oklahoma City | 1980 | 1984 | |
| Trans-Colorado Airlines | Colorado | | VJ | TCE | TRANS COLORADO | Gunnison–Crested Butte | 1980 | 1988 | Became a Continental Express carrier |
| Trans-Florida Airlines | Florida | | | TFA | TRANS FLORIDA | Daytona Beach | 1966 | 2006 | Established as Daytona Aviation in 1962 |
| Trans-Marine Airways | New York | | | | | Daytona Beach | 1945 | 1946 | Charter services |
| Trans-Michigan Airlines | Michigan | | | | | Traverse City | 1969 | 1970 | Operated Beech 99, Cherokee Six |
| Trans-Mo Airlines | Missouri | | XU | | | | 1966 | 1986 | |
| Trans-Nebraska Airlines | Nebraska | | | | | | 1971 | 1973 | Founded by Tom Brown. Operated Cessna 402A |
| Trans-Nevada Air Service | Nevada | | | | | Las Vegas McCarran | 1968 | 1971 | Commuter services. Operated Beech C-45 Expeditor |
| Trans-Pacific Airlines | Hawaii | | | | | Honolulu | 1946 | 1950 | Renamed to TPA-The Aloha Airline. Operated C-47 |
| Trans-Texas Airways | Texas | | TT | | | Houston-Hobby Dallas-Love Field | 1947 | 1968 | Renamed to Texas International Airlines. Operated DC-3, Convair 240 |
| Transair | New York | | | | | New York-LaGuardia | 1946 | 1946 | |
| Transair Airlines | Florida | | | | | St. Pete–Clearwater | 1946 | 1949 | Operated DC-3, DC-4, Lockheed Super Electra, Lockheed Lodestar |
| Transair Cargo | Florida | | | | | Miami | 1972 | 1977 | Established as Skyways International in 1962 |
| Transair Hawaii | Hawaii | | | | | Honolulu | 1946 | 1948 | Operated C-46 |
| Transamerica Airlines | California | | TV | TVA | TRANS-AMERICA | Oakland | 1979 | 1986 | Rebranded from Trans International Airlines |
| Transcontinental & Western Air | New York | | | | | New York-LaGuardia | 1930 | 1950 | Renamed to Trans World Airlines; operated DC-1, DC-2 |
| Transcontinental Air Transport | | | | | | | 1928 | 1929 | Merged with Maddux Air Lines to form TAT-Maddux Air Lines |
| TransMeridian Airlines | Georgia | | T9 | TRZ | TRANS MERIDIAN | Orlando Sanford | 1995 | 2005 | Established as Prime Air |
| Transocean Air Lines | California | | TL | | TALOA | Oakland | 1946 | 1960 | Went bankrupt |
| TransOcean Airways | Louisiana | | QG | GAT | GULFTRANS | New Iberia | 1989 | 1990 | Established as Gulf Air Transport. Charter operator |
| Transtar Airlines | Florida | | | TRH | TRANSTAR | Orlando | 1992 | 1993 | |
| TranStar Airlines | Texas | | MC | TST | TRANSTAR | Houston-Hobby | 1986 | 1987 | Shut down by parent company Southwest Airlines |
| Transtate Airlines | New York | | | | | New York-LaGuardia | 1963 | n/a | Operated Lockheed L-1049 |
| Transwest Air Express | California | | | ACW | | Oakland | 1977 | 1981 | Established as Zoom Zoom Air in 1973. Renamed to Air Charter West. Operated DC-3 |
| Transwestern Airlines | Utah | | WZ | TRW | TRANS WEST | Logan-Cache | 1977 | 1983 | Acquired by Horizon Air |
| Travel Air Aviation | | | | | | | 1969 | 1972 | As part of Allegheny Commuter. Operated Beech 99 |
| Tri-Motor Safety Airlines | New York | | | | | Garden City | 1929 | 1929 | Rename to New York Safety Airlines. Operated Ford Trimotor (NC1780) |
| Tri-State Airlines | Iowa | | | | | Rickenbacker | 1930 | 1936 | Renamed to Hanford Tri-State Airlines |
| Tri-State Flying Service | West Virginia | | | | | Huntington Tri-State | 1971 | 1972 | Established as Air Enterprises in 1969 |
| Tricon International Airlines | Texas | | RI | | | Dallas Love Field | 1967 | 1978 | Operated Beech 18, DC-3 |
| Trinity Air Bahamas | Florida | | | | | Fort Lauderdale–Hollywood | 1993 | 1993 | |
| TriStar Airlines | Nevada | | T3 | TRY | TRISTAR AIR | Las Vegas McCarran | 1995 | 1997 | |
| Tropic Air | Hawaii | | | | | Honolulu | 1980 | 1989 | Associated with Air Molokai |
| Tropic Air | California | | | | | Burbank | 1988 | 1988 | |
| Tropical Airways | New York | | | | | New York Kennedy | 1986 | 1989 | |
| Tropics International | Florida | | | | | Miami | 1968 | 1971 | Operated Beech 18 |
| Trump Shuttle | New York | | TB | TPS | TRUMP | New York-LaGuardia | 1989 | 1992 | To US Airways Shuttle |
| Tulip City Executive Express | Minnesota | | | | | Holland | 1995 | 1995 | Operated Beech 18 |
| Tulsa-Oklahoma City Airline | Oklahoma | | | | | Tulsa | 1928 | 1929 | Ownership transferred to Universal Aviation Corporation |
| Turbo Air | Idaho | | | | | Boise | 1995 | 1995 | Charter carrier |
| Turks Air Cargo | Florida | | | | | Miami | 1972 | 2015 | Founded by Robert Caravan |
| Turner Airlines | Indiana | | | | | Indianapolis | 1947 | 1950 | Renamed to Lake Central Airlines |
| TWC Aviation, Inc | California | | | | | San José | 1998 | 2015 | Acquired and rebranded into Landmark Aviation |
| Twentieth Century Airlines | North Carolina | | | | | Charlotte Douglas | 1946 | 1963 | Founded by Glen Shave and Christopher Bachman. Operated DC-3, DC-4. A member carrier of North American Airlines |
| Tyee Airlines | Alaska | | OF | | | Ketchikan | 1975 | 1986 | Operated DHC Beaver |
| Tyme Airlines | Ohio | | | | | Cleveland Burke | 1965 | 1967 | Merged into Wright Airlines |
| U |
| U Fly Air Freighters | Texas | | | | | Dallas Fort Worth | 1973 | 1975 | Cargo operator |
| U. S. Airlines | New York Florida Georgia | | | | | Fort Lauderdale Atlanta St Peterburg | 1945 | 1954 | Scheduled freight carrier |
| U.S. Aviation | Wyoming | | BH | | | Riverton | 1977 | 1979 | Renamed to Air U.S. |
| UltrAir | New York | | | ULT | ULTRAIR | New York Kennedy | 1993 | 1994 | |
| UltrAir | Texas | | RL | ULT | | Houston Bush | 1993 | 1994 | Operated 727-200 |
| Unalakleet Air Taxi | Alaska | | | | | Unalakleet | 1953 | 1979 | Renamed to Ryan Air |
| United Couriers | California | | | | | Burbank | 1971 | 1971 | Merged with California Air Charter |
| United Feeder Service | Illinois | | U2 | UFS | FEEDER EXPRESS | Chicago O'Hare | 1993 | 2000 | |
| United Shuttle | California | | UA | UAL | UNITED | San Francisco | 1994 | 2001 | Subsidiary of United Airlines, formerly Shuttle by United; folded back into United |
| United States Air Transport | New York | | | | | New York Curtis | 1929 | 1930 | Operated Ryan Brougham |
| United States Overseas Airlines | New Jersey | | US | US | | Cape May | 1946 | 1964 | Supplemental air carrier, flew scheduled service to Okinawa and military charters |
| United Union Airways | Washington | | | | | Felts Field | 1929 | 1929 | Founded by W R Frentzel, C M Baker & Francis Baker |
| Universal Air Lines Corporation | Missouri | | | | | St. Louis Lambert | 1928 | 1934 | Merged with 90 other airlines to form American Airlines |
| Universal Airlines | Texas | | | | | El Paso | 1957 | 1959 | dba of S.S.W. |
| Universal Airlines | Michigan California | | UV | UV | | Willow Run Oakland | 1966 | 1972 | Established as Zantop Air Transport |
| Universal Airlines | Michigan | | | | | Willow Run | 1979 | 1992 | Cargo operator |
| Universal Aviation Corporation | Missouri | | | | | | 1929 | | An airline holding company |
| Upper Valley Aviation | Texas | | | | | McAllen Miller | 1964 | 1975 | Operated Beech 99, Beech E18S |
| Uraba, Medellin and Central Airways | Panama Canal Zone | | UR | UR | | N/A | 1932 | 1959 | Owned, equipped and crewed by Pan Am |
| U.S. Aircoach | California | | | | | Hollywood Burbank | 1949 | 1959 | Supplemental air carrier shut by CAB in 1959 for finances & compliance |
| US Airways | Arizona | | US | USA | US AIR | Phoenix Sky Harbor | 1997 | 2015 | Merged into American Airlines |
| US Airways Express | | Phoenix Sky Harbor | Rebranded as American Eagle |
| US Airways Shuttle | Virginia | | Washington National | Founded as Eastern Air Lines Shuttle, rebranded as American Airlines Shuttle |
| US Check Airlines | Ohio | | | | | | 1974 | 1974 | Delivery of documents and small packages |
| US Helicopter | New York | | UH | USH | US HELI | Downtown Manhattan Heliport | 2004 | 2009 | |
| USA3000 Airlines | Pennsylvania | | US | GWY | GETAWAY | Philadelphia | 2001 | 2012 | |
| USAfrica Airways | Virginia | | | | | Washington Dulles | 1994 | 1995 | |
| USAir | Arizona | | | | | Phoenix Sky Harbor | 1979 | 1997 | Renamed to US Airways |
| Utah Pacific Airways | Utah | | | | | Ogden | 1931 | n/a | |
| Uvalde Aero Service | Texas | | | | | Uvalde | 1965 | 1977 | Operated Lockheed L-12 Electra Junior, Piper Navajo, Piper Twin Comanche |
| V |
| Vagabond Air Travel Club | Ohio | | | | | | 1970 | 1974 | Air travel club. Operated DC-6B, L-188 Electra |
| Vail Airways | Colorado | | | | | | 1966 | 1968 | Founded by Gordon Autry |
| Val-Air Lines | Texas | | | | | Mercedes | 1950 | n/a | Feeder service. Operated Beech Bonanza, Ryan Navion |
| Valdez Airlines | Alaska | | | | | Anchorage | 1980 | 1984 | Merged with Air North to form Liberty Air |
| Valdosta Phoenix Airlines | Georgia | | | | | Valdosta | 1972 | 1973 | |
| Vale International Airlines | Tennessee | | | VIN | | Nashville | 1979 | 1980 | |
| Valley Airlines | California | | | | | Oakland | 1968 | 1974 | Merged with Ram Airways to form Pacific Northwest Airways |
| Valley Airlines | Maine | | | | | Fort Kent | 1981 | 1989 | Renamed to Northeast Express |
| Valley Airpark Commuter Service | Colorado | | | | | Denver | 1975 | 1977 | |
| Valley Catalina Airlines | California | | | | | Van Nuys | 1981 | 1981 | |
| Valley Isle Aviation | Hawaii | | | | | Kahului | 1965 | 1967 | |
| ValuJet Airlines | Georgia | | J7 | VJA | CRITTER | Atlanta | 1993 | 1997 | Merged into AirTran Airways |
| Vance Air Services | Montana | | | | | Great Falls | 1928 | n/a | Founded by Clare Vance. Operated Stinson Detroiter |
| Vance International Airways | Washington | | | | | Boeing Field | 1960 | 1970 | Briefly known as Charter International Airlines. Became McCulloch International Airlines |
| Vanguard Airlines | Missouri | | NJ | VGD | VANGUARD AIR | Kansas City | 1994 | 2002 | Low cost /low fare airline |
| Varney Air Lines | Idaho | | | | | Salt Lake City | 1926 | 1934 | Merged into United Airlines |
| Vee Neal Airlines | Pennsylvania | | | | | Latrobe | 1980 | 1983 | renamed to Jetstream International Airlines |
| Vercoa Air Service | Illinois | | | | | Danville | 1964 | 1975 | Renamed to Britt Airways |
| Vero Monmouth Airlines | Georgia | | VM | VMA | VERO MAMMOUTH | Vero Beach | 1973 | 1975 | Operated de Havilland Heron, Martin 4-0-4 |
| Veterans Air Lines | New Jersey | | | | | Newark | 1945 | n/a | Operated DC-3, DC-4 |
| Via Airlines | Florida | | VC | SRY | | Orlando | 2015 | 2019 | Established as Charter Air Transport. Operated Embraer Brasilia, Embraer ERJ 145 |
| Viair | New Jersey | | | | | Newark | 1935 | 1935 | Charter and resort air service |
| ViaAir | Florida | | VC | SRY | STINGRAY | Beckley Raleigh County | 1997 | 2019 | Went bankrupt |
| Victory Aviation Services International | New York | | | | | New York-LaGuardia | 1995 | 1999 | |
| Viking Air Lines | California | | | | | Lockheed Air Terminal | 1946 | 1956 | Established as Aero-Van Express |
| Viking Air Transport | California | | | | | Glendale, California | 1946 | 1947 | In 1947 became non operating parent company of Aero-Van Express |
| Viking International Airlines | Minnesota | | VO | VIK | VIKING | Minneapolis–Saint Paul | 1969 | 1994 | Acquired by Eagle Air International |
| Vintage Airways | Florida | | | | | Kissimmee | 1992 | 1995 | Founded by Richard Branson operated in 1940s livery |
| Vintage Props and Jets | Florida | | VQ | VPP | VINTAGE | New Smyrna Beach | 1992 | 2008 | Went bankrupt |
| Virgin America | California | | VX | VRD | REDWOOD | San Francisco | 2004 | 2018 | Acquired by Alaska Airlines |
| Virgin Islands Seaplane Shuttle | US Virgin Islands | | | VSS | WATERBIRD | Saint Croix | 1982 | 1989 | |
| Virginia Air Cargo | Maryland | | | | | Baltimore–Washington | 1974 | 1979 | Operated BN islander, Short Skyvan |
| Visco Flying Service | California | | | | | Los Angeles | 1964 | 1967 | Operated shuttle service. Renamed to Imperial Airlines |
| Viscount Air Service | Arizona | | | VCT | VISCOUNT AIR | Tucson | 1992 | 1996 | Operated Boeing 727, Boeing 737 |
| Vision Airlines | Nevada | | V2 | RBY | RUBY | North Las Vegas | 1994 | 2017 | Established as Vision Air. Incorporated in Virginia. Revoked by State |
| Volunteer Airlines | Tennessee | | | | | Berry Field | 1954 | 1955 | Tennessee intrastate airline briefly operated by Capitol Airways |
| VQ Airlines | Florida | | | | | Daytona Beach | 1970 | 1973 | Airline division of Volusia Aviation Service |
| Vroman Aviation | Texas | | | | | | 1965 | 1972 | Established as Champs Aviation |
| W |
| Walatka Air Service | Alaska | | | | | | 1930 | 1930 | |
| Walker's International | Florida | | XW | WRC | | Fort Lauderdale | 1982 | 2003 | Established as Jet Hansa Corporation in 1967 |
| Warsaw Aviation | Indiana | | | | | Warsaw | 1971 | 1971 | Third-level services. Operated Piper Twin Comanche, Piper Apache |
| Waterman Airlines | Alabama | | | | | Mobile | 1946 | 1948 | Operated Lockheed Lodestar, DC-3 |
| Washington Airlines | Maryland | | | | | Baltimore–Washington | 1968 | 1969 | STOL operation |
| Washington Flying Service | Virginia | | | | | Washington | 1928 | 1929 | Scenic flights |
| Washington-Baltimore Airways | Maryland | | | | | Baltimore–Washington | 1961 | 1971 | Operated Beech 18, Piper Apache |
| Watermakers Air | Florida | | | | | Fort Lauderdale | 1999 | 2018 | Operated Cessna Grand Caravan |
| Waterman Airlines | Alabama | | | | | | 1945 | 1947 | Intrastate carrier |
| Watertown Airways | South Dakota | | | | | Watertown | 1935 | 1936 | |
| Webber Airlines | Alaska | | | | | Ketchikan Harbor Seaplane Base | 1970 | 1979 | Founded by Jim Webber. Merged with Flair Air to form Southeast Alaska Airlines. Operated DHC Beaver], Grumman Goose |
| Wedekind-Schmidlapp Flying Service | Ohio | | | | | Hook Field | 1932 | 1961 | Founded by Larry Schmidlapp and George "Pappy" Wedekind. Operated Waco VKS-7 |
| Wedell-Williams Air Service Corporation | Louisiana | | | | | Patterson | 1929 | 1936 | Founded by Jimmy Wedell and Harry Palmerston Williams. Acquired by Eastern Air Lines. Operated Lockheed Vega 5B |
| Wes-Tex Aircraft | Texas | | | | | Lubbock Airport | 1964 | 1971 | Operated Piper Navajo, Piper Twin Comanche, Piper Cherokee |
| West Central Airlines | Nebraska | | | | | Omaha | 1966 | 1971 | Operated de Havilland Dove, Cherokee Six, Cessna 182 |
| West Coast Air Cargo | Oregon | | | WCC | WEST COAST | Portland–Troutdale | 1982 | 1999 | Cargo carrier |
| West Coast Airlines | Washington | | WC | | | Seattle–Tacoma | 1941 | 1968 | Merged with Pacific Air Lines and Bonanza Air Lines to form Air West which was then renamed Hughes Airwest in 1970 |
| WestAir Airlines | California | | | | | Fresno Yosemite | 1978 | 1986 | Established as Stol Air Commuter. Renamed to WestAir Commuter Airlines |
| WestAir Commuter Airlines | California | | OE | SDU | SUNDANCE | Fresno Yosemite | 1978 | 1992 | Formerly Stol Air Commuter, to Mesa Air Group |
| Westair Transport | | | | | | Seattle | 1947 | 1960 | Supplemental air carrier stopped flying in 1960 after IRS seized assets, a dba of Aviation Corp. of Seattle |
| Westates Airlines | California New Jersey | | WS | WSA | WESTATES | Los Angeles Atlantic City | 1984 | 1995 | Renamed to Gray Line Air |
| Western Air Express | California | | | | | Los Angeles | 1926 | 1930 | Operated Douglas M-2, Fokker F-10 |
| Western Air Express Texas | Texas | | | | | Midland | 2004 | 2016 | Operated Beech Queen Air 70 |
| Western Air Industries | California | | | | | Redding | 1960 | 1960 | Aerial firefighting carrier. Renamed to Aero Union. Operated B-25 Mitchell |
| Western Air Service | Nebraska | | | | | Eppley Airfield | 1930 | 1930 | Operated Ford Trimotor |
| Western Air Stages | Colorado | | | | | Grand Junction | 1972 | 1976 | Operated Beech Queen Air, Riley Dove 400 |
| Western Aircraft | Idaho | | | | | Gooding | 1964 | 1971 | Operated Beech 18, Piper Apache |
| Western Aircraft Salvage | California | | | | | Santa Maria | 1974 | 1980 | Operated Beech 18, Piper Apache |
| Western Airlines | California | | WA | WAL | WESTERN | Los Angeles | 1941 | 1987 | Merged into Delta Air Lines |
| Western Airlines (2007) | Washington | | XP | CXP | RUBY MOUNTAIN | Bellingham | 2007 | 2007 | |
| Western Alaska Airlines | Alaska | | | | | Kodiak | 1940 | 1973 | Merged with Kodiak Airways to form Kodiak Western Alaska |
| Western Express Air | Arizona | | | | | Laughlin/Bullhead | | 2007 | |
| Western Pacific Airlines | Colorado | | W7 | KMR | KOMSTAR | Colorado Springs | 1995 | 1998 | |
| Westflight Aviation | Alaska | | | | | Ketchikan | 1981 | 1986 | Acquired by Temsco Airlines |
| WestJet Express | Nevada | | | | | Fresno Yosemite | 1998 | 1999 | Renamed to Allegiant Air |
| Westward Airways | Nebraska | | CN | WWD | WESTWARD | Western Nebraska | 2004 | 2005 | |
| Wheeler Airlines | North Carolina | | | | | Raleigh–Durham | 1969 | 1991 | Established as Wheeler Flying Service |
| Whidbey Flying Service | Washington | | | | | Oak Harbor | 1964 | 1969 | Founded by Wes Luipen. To Puget Sound Airlines |
| Wien | Alaska | | | | | Anchorage | 1982 | 1984 | |
| Wien Air Alaska | | WC | WAA | | 1973 | 1982 | Several name changes over the years, final name Wien |
| Wien Airways of Alaska | | | | | 1926 | 1935 | Established as Northern Air Transport |
| Wien Alaska Airways | | | | | 1935 | 1968 | Merged with Northern Consolidated Airlines to form Wien Consolidated Airlines |
| Wien Consolidated Airlines | | | | | 1968 | 1973 | Formed by the merger of Wien Alaska Airlines and Northern Consolidated Airlines |
| Wilbur's Inc. | Alaska | | | | | Anchorage | 1984 | 1992 | |
| Wild Goose Flying Service | Texas | | | | | San Antonio | 1984 | 1992 | |
| Wildblue Yonder-Aero Taxi | Idaho | | | | | Lemhi County | 1998 | 1998 | |
| Williams Air | New Jersey | | | | | | 1981 | 1983 | Operated BN Islander |
| Wilmington-Catalina Airline | California | | | | | Hamilton Cove Seaplane Base | 1931 | 1942 | Certificated by the Civil Aeronautics Board in 1939, owned by the Wrigley family. |
| WinAir Airlines | Utah | | | WNA | WINAIR | Salt Lake City | 1997 | 1999 | |
| Winged Cargo Company | Pennsylvania | | | | | Northeast Philadelphia | 1931 | 1946 | Freight service. Operated DC-3 towing Waco CG-4 |
| Wings Air | Georgia | | | WAI | | Atlanta | 2008 | 2010 | |
| Wings Airways | Pennsylvania | | WQ | WAW | WING SHUTTLE | Blue Bell Wings Field | 1977 | 1991 | |
| Wings Express | California | | | | | Burbank | 1993 | 1993 | Cargo carrier. Acquired by Ameriflight |
| Wings of Alaska | Alaska | | K5 | SQH | SASQUACH | Juneau | 1982 | 2017 | Founded by Dean Williams and Billy Bernhardt. Established as Southeast Skyways. Operated Cessna 207, DHC-3 Otter |
| Wings West Airlines | California | | RM | WWM | WINGS WEST | McChesney Field | 1979 | 1998 | Later operated as American Eagle, then merged into Simmons Airlines |
| Winkys Fish Airlines | Alaska | | | | | Anchorage | 1990 | 1990 | Operated Boeing 727. Salmon transport |
| Winnipesaukee Airlines | Florida | | | | | Tampa | 1976 | 1977 | |
| Wisconsin Central Airlines | Wisconsin | | | | | Clintonville | 1946 | 1952 | Renamed to North Central Airlines |
| Wise Airlines | Texas | | 4W | | | San Angelo | 1983 | 1985 | Operated Beech 99, Twin Otter. Went bankrupt |
| Woodley Airways | Alaska | | | | | Merrill Field | 1932 | 1945 | Renamed to Pacific Northern Airlines |
| Woods Air Service | Alaska | | | | | Palmer | 1961 | 2000 | |
| World Airways | Georgia | | WO | WOA | WORLD | Atlanta | 1948 | 2014 | |
| World American Airlift | California | | | | | Fresno Yosemite | 1968 | 1970 | |
| World Wide Airlines | Alaska | | | | | Anchorage | 1956 | 1962 | Established as Pearson-Alaska Airlines in 1948. Operated DC-4, C-46, L-749, L-1049 |
| Worldwide Airlines | Illinois | | | | | Chicago Midway | 1983 | 1986 | Subsidiary of Carefree Vacations Inc. |
| Wrangler Aviation | North Carolina | | | | | Piedmont Triad | 1973 | 1991 | Established as Bluebell Aviation in 1969. Renamed to Tradewinds Airlines |
| Wright Airlines | Ohio | | FW | WRT | WRIGHT | Cleveland Burke | 1966 | 1983 | Went bankrupt |
| WTC Air Freight | New Jersey | | | | | | 1967 | 1987 | Acquired by BAX Global |
| Wyoming Air Service | Wyoming | | | | | Cheyenne | 1930 | 1937 | Renamed to Inland Air Lines. Operated Stinson Junior, Boeing 247D |
| Wyoming-Montana Air Lines | Wyoming | | | | | Casper–Natrona | 1930 | 1938 | Renamed to Inland Air Lines in 1938 |
| X |
| Xtra Airways | Florida | | XP | CXP | CASINO EXPRESS | Houston-Hobby | 1987 | 2021 | Founded as Casino Express Airlines commenced operations in 1989. Rebranded as Avelo Airlines. |
| Y |
| Yankee Airlines | Massachusetts | | | | | Pittsfield | 1962 | 1968 | Acquired by Executive Airlines. Operated de Havilland Dove |
| Yosemite Airlines | California | | JE | | | Columbia | 1975 | 1981 | |
| Your Florida Air | | | | | | | 2005 | 2005 | never launched |
| Yukon Air Service | Alaska | | | | | Fairbanks | 1967 | 1973 | Founded by Roger Dowding. Renamed to Air North |
| Yutana Airlines | Alaska | | | | | Anchorage | 1987 | 1994 | Renamed to Alaska Central Express |
| Yute Air | Alaska | | 4Y | UYA | | Bethel | 2004 | 2017 | |
| Yute Air Alaska | Alaska | | | | | Bethel | 1974 | 2000 | Established as Bob Harris Flying Service. Renamed to Flight Alaska |
| Z |
| Zantop Air Transport | Michigan | | | | | Willow Run | 1956 | 1966 | Took over the certificate of Coastal Air Lines in 1962. To Universal Airlines |
| Zantop Airways | Michigan | | | JTZ | JETZAN | Detroit | 1968 | 1981 | Part 298 operator that became Orion Air |
| Zantop Flying Service | Michigan | | | | | Willow Run | 1946 | 1956 | Became Zantop Air Transport |
| Zantop International Airlines | Michigan | | VK | ZAN | ZANTOP | Willow Run | 1972 | 2005 | |
| Zetta Jet | California | | | | | Burbank | 2015 | 2017 | Established as Advanced Air Management |
| Zia Airlines | New Mexico | | | | | Las Cruces | 1972 | 1980 | Renamed to Air New Mexico. Air ambulance services |
| Zimmerly Air Lines | Idaho | | | | | Boise | 1942 | 1946 | Renamed Empire Airlines |
| Zoom Zoom Air | California | | | | | Oakland | 1973 | 1974 | Renamed from Arabesco Air Renamed to Air Charter West. Operated Basler BT-67 |