Peter Sarsgaard was born on March 7, 1971, at Scott Air Force Base in Bellville, Illinois, to Judy Lea Reinhardt and John Dale Sarsgaard, an engineer who worked for the Air Force and later Monsanto and IBM.
He is a graduate of Washington University in St. Louis, where he majored in history and literature.
Initially trained with the Actors' Studio in New York, Peter began his career in comedy and became a co-founder of the improvisational group Mama's Pot Roast.
He made his screen debut in Tim Robbins' Dead Man Walking (1995) and went on to appear in off-Broadway productions such as Horton Foote's "Laura Dennis" and John Cameron Mitchell's "Kingdom of Earth".
Peter's breakthrough role was as a homophobic killer in Boys Don't Cry (1999),starring Hilary Swank as a trans-gendered teen.
He has since appeared in a wide range of films, including Shattered Glass (2003),K-19: The Widowmaker (2002),The Salton Sea (2002),Garden State (2004),Kinsey (2004),Knight and Day (2010),Green Lantern (2011),Blue Jasmine (2013),Experimenter (2015),Jackie (2016),The Magnificent Seven (2016),Loving Pablo (2017),The Sound of Silence (2019),and Human Capital (2019).
On TV, Peter has appeared in recurring and regular roles in several critically acclaimed series and mini-series, including The Killing, The Slap, Wormwood, The Looming Tower, and Running Naked in the Universe.
In 2009, Peter married actress Maggie Gyllenhaal and they have two children together. He co-starred in her movie The Lost Daughter (2021),starring Olivia Colman.