Peter Gallagher, Actor: American Beauty. Peter Gallagher was born on August 19, 1955 in New York City, New York, USA as Peter Killian Gallagher. He is an actor, known for American Beauty (1999), The O.C. (2003) and While You Were Sleeping (1995). He has been married to Paula Harwood since May 7, 1983. They have two children.