John Peter Sarsgaard (born March 7, 1971) is an American actor. His first feature role was in Dead Man Walking in 1995. He then appeared in the 1998 independent films Another Day in Paradise and Desert Blue. That same year, Sarsgaard received a substantial role in The Man in the Iron Mask (1998), playing Raoul, the ill-fated son of Athos. Sarsgaard later achieved critical recognition when he was cast in Boys Don't Cry (1999) as John Lotter. He landed his first leading role in the 2001 film The Center of the World. The following year, he played supporting roles in Empire, The Salton Sea, and K-19: The Widowmaker.

For his portrayal of Charles Lane in Shattered Glass, Sarsgaard won the National Society of Film Critics Award for Best Supporting Actor and was nominated for the 2004 Golden Globe Award for Best Supporting Actor. Sarsgaard has appeared in an eclectic range of films, including the 2004 comedy-drama Garden State, the biographical film Kinsey (2004), the drama The Dying Gaul (2005), and big-budget films such as Flightplan (2005), Jarhead (2005), The Skeleton Key (2005), Orphan (2009), An Education (2009), Knight and Day (2010), Green Lantern (2011), Lovelace (2013), Kelly Reichardt's Night Moves (2013), Blue Jasmine (2013), Black Mass (2015), and The Magnificent Seven (2016). Sarsgaard also appeared in the American TV series The Killing (2013) as a man on death row perhaps wrongfully convicted for the brutal murder of his wife—a performance which he says included "some of the best acting I have ever done in my life." In 2021, he had a recurring role on the Hulu miniseries Dopesick.

Sarsgaard has appeared in Off-Broadway productions including Kingdom of Earth, Laura Dennis, Burn This, and Uncle Vanya. In September 2008, he made his Broadway debut as Boris Alexeyevich Trigorin in The Seagull. He is married to actress Maggie Gyllenhaal.

Zadebiutował jako aktor na scenie w czasie ostatniego roku studiów w St. Louis' Washington University. Był członkiem Mama's Pot Roast i słuchaczem Actors' Studio w Nowym Jorku. Występował w teatrach off-Broadway, m.in. w "Kingdom of Earth" Johna Mitchella. Po raz pierwszy na ekranie pojawił się w filmie Tima Robbinsa "Przed egzekucją". Trzy lata później zagrał niewielką rolę Raoula - syna Atosa (John Malkovich) i ukochanego Christine (Judith Godreche), który na rozkaz Ludwika XIV wyrusza na wojnę i ginie w obrazie "Człowiek w żelaznej masce". Sarsgaard związany jest przede wszystkim z kinem niezależnym. Zwrócił na siebie uwagę rolą Johna Lottera w filmie Kimberly Peirce "Nie czas na łzy", opartym na autentycznych wydarzeniach (historii śmierci Teeny Brandon). W kontrowersyjnym obrazie Wayne Wanga "Centrum świata" wcielił się w młodego biznesmena, prowadzącego perwersyjną grę z striptizerką. W świadomości szerszej publiczności jednak zaistniał dopiero, dzięki udziałowi w widowiskowym dramacie Kathryn Bigelow "K-19: The Widowmaker", gdzie pojawił się u boku Harrisona Forda.

John Peter Sarsgaard (Belleville, 7 de março de 1971) é um ator estadunidense. É principalmente conhecido pelos filmes Boys Don't Cry, Shattered Glass e Jarhead. Ele costuma fazer filmes de variados temas e gêneros, geralmente independentes. Já ganhou uma indicação ao Golden Globe Awards de Melhor Ator pelo filme Shattered Glass, duas indicações ao Independent Spirit Awards de Melhor Ator Coadjuvante, por Shattered Glass e por Kinsey, também ganhou o prêmio de Melhor Ator no Festival de Estocolmo por Garden State. No dia 2 de maio de 2009 casou-se com Maggie Gyllenhaal, atriz e irmã mais velha do ator Jake Gyllenhaal.

John Peter Sarsgaard (7 de marzo del 1971) es un actor estadounidense.