Holohan (Irish: Ó hUallacháin; feminine Ní Uallacháin) is a surname of Irish Gaelic origin, from the Irish uallach meaning "proud".

A version of the family crest depicts two white lions holding up a golden tower.

According to historian C. Thomas Cairney, the O'Holohans were one of the chiefly families of the Ui Failghe who in turn were a tribe from the Dumnonii or Laigin who were the third wave of Celts to settle in Ireland during the first century BC.

Notable people with the surname include:

See also