Dermot Mulroney grew up in Alexandria, Virginia, and went to Maury Elementary School. He played the cello in school and city youth orchestras and acted in children's community theater. He made his high school stage debut in an awful play called "Are Teachers Human?" at George Washington Middle School. He graduated from T.C. Williams High School in 1981. His dad was a lawyer. He grew up with three brothers - Sean, Conor and Kieran Mulroney (now also an actor) - and a sister named Moira.


Graduated from Northwestern University in 1985, where he attended the School of Speech. Was a member of Phi Gamma Delta fraternity at Northwestern University. First child born, with Catherine Keener, a son named Clyde. [June 1999] He and his younger brother, Sean Mulroney, are co-owners of "The Double Door", one of Chicago's more popular music clubs. Plays cello in the song Place Your Mind from Melissa Etheridge's 1992 album Never Enough, and in the score to Mission: Impossible III (2006). Born on the same day as actor/comedian Rob Schneider. Lives in Los Angeles. Is of predominantly Irish ancestry. All of his siblings have traditional Irish names Former brother-in-law of Elizabeth Keener. Welcomed second child, a girl named Mabel Ray, in April 2008. Mother is Dermot's girlfriend Tharita. He and Catherine Keener sold their four-bedroom, 4,866-square-foot home in Los Angeles' Hollywood Hills area for $3,050,000. They had purchased the property in 1997 for about $1.35 million. [2005]