Kelly O'Sullivan (born 1983/1984) is an American actress, screenwriter, and producer. She wrote and starred in Saint Frances (2019), which won the Audience Award and the Special Jury Award at the 2019 SXSW Film Festival.

O'Sullivan was born and raised in Little Rock, Arkansas, to an accountant mother and a father who worked in health insurance. She was raised Irish Catholic and attended Immaculate Conception School until eighth grade.