Joan Margaret Clark (born March 27, 1922) is an American retired diplomat who served as United States Ambassador to Malta between 1979 and 1981. Born in Ridgefield Park, New Jersey, she is a member of the American Academy of Diplomacy. In 2007, Clark was presented the Lifetime Contributions to American Diplomacy Award by the American Foreign Service Association.

Clark left her post in Malta when she became Director General of the Foreign Service and Director of Personnel. She also served as Director of the Office of Management Policy (April 10, 1977 – March 20, 1979) and Assistant Secretary of State for Consular Affairs (1983–1989).

Diplomatic posts
Preceded byBruce LaingenUnited States Ambassador to Malta March 26, 1979 – February 21, 1981Succeeded byFrank P. Wardlaw (as Chargé d’Affaires ad interim) James Malone Rentschler
Government offices
Preceded byDiego C. AsencioAssistant Secretary of State for Consular Affairs December 22, 1983 – October 18, 1988Succeeded byElizabeth M. Tamposi