Peter Gallagher

Gallagher was born in New York City. His mother, Mary Ann (née O'Shea), was a bacteriologist, and his father, Thomas Francis Gallagher, Jr., was an advertising executive. Gallagher is the youngest of their three children. He is of Irish Catholic background and was raised in Armonk, New York. Gallagher graduated from Tufts University, where he was active in theater, appearing in such shows as Stephen Sondheim's Company and singing with the all-male a cappella group the Beelzebubs. He studied acting at the William Esper Studio and with Mira Rostova.Gallagher appeared on Broadway with Glenn Close in Tom Stoppard's The Real Thing and made his feature film debut in the Taylor Hackford film The Idolmaker, but first achieved fame for his role in Steven Soderbergh's sex, lies, and videotape (1989). He also starred as Sky Masterson in the 1992 Broadway hit revival of Guys and Dolls.

Gallagher played a potential career threat to Tim Robbins's studio executive in The Player (1992); the comatose fiancé of Sandra Bullock in While You Were Sleeping (1995); a major real estate salesman having an affair with Annette Bening in American Beauty (1999); a media executive in Mr. Deeds (2002); and a political reporter exposing media ethics during a presidential debate in The Last Debate.

From 2003 to 2007, Gallagher starred as Sandy Cohen, a Jewish public defender and corporate lawyer, on the Fox television show The O.C. He hosts an annual award ceremony named "The Sandy Cohen Awards" or The Sandys, which, in honor of his character on The O.C., gives a scholarship to a law school student at UC Berkeley who wants to become a public defender.

Gallagher released an album titled 7 Days in Memphis in 2005, on the Sony BMG label. This includes a studio recording of his performance of "Don't Give Up On Me" (originally by Solomon Burke), which was featured in an episode of The O.C. He also has a video for his single "Still I Long For Your Kiss", in which he starred with his TV-wife Kelly Rowan.

In 2005, Gallagher received the P.T. Barnum Award from Tufts University for his exceptional work in the field of media and entertainment. In 2007, Gallagher received the "Light on the Hill" award at Tufts University. The award is given to notable alumni from Tufts who have demonstrated ambition, achievement, and active citizenship.

From February 13 through July 5, 2015, Gallagher starred on Broadway in On the Twentieth Century although he missed several performances in late February due to illness.

In 2020 Gallagher played Mitch Clarke, who had progressive supranuclear palsy, in a regular role in the first season of Zoey's Extraordinary Playlist. Though his character died in the season 1 finale, Gallagher appeared in several episodes of the second season and the Christmas special Zoey's Extraordinary Christmas.

In 2021, Gallagher took part in the television series Grey's Anatomy as Dr. David Hamilton.

From 2018 through 2022, Gallagher appeared in four seasons of the Netflix series Grace and Frankie as Nick, the boyfriend of Jane Fonda's character Grace.

In 2024, Gallagher is set to return to Broadway, in a new play based on the life of Delia Ephron, titled Left on Tenth.