Born on the same day as actor/comedian Rob Schneider.

He and his older brother Sean are co-owners of 'The Double Door', one of Chicago's more popular music clubs.

Played the cello on the score to Mission: Impossible III (2006).

Was a member of Phi Gamma Delta fraternity at Northwestern University.

Sister Moira works in the Philadelphia DA's office as an assistant district attorney.

He is sometimes confused with actor Dylan McDermott; there is a slight resemblance and a similar sounding name.

Plays in a band called the Cranky George Trio.

Plays cello in the song "Place Your Mind" from Melissa Etheridge's 1992 Album "Never Enough".

Was in a band called 'The Low & Sweet orchestra'.

Brother-in-law of Elizabeth Keener.

Mulroney's younger brother Kieran Mulroney is also an actor. The brothers starred together in the John Hughes comedy, Career Opportunities (1991) with Jennifer Connelly and Frank Whaley.

Lives in Los Angeles.

First child born, with Catherine Keener, a son named Clyde. [June 1999]

Is of predominantly Irish ancestry. All of his siblings have traditional Irish names

Attended "TC Williams High School", which later became the setting of a Disney movie with Denzel Washington.

Good friends with actress Julia Roberts.

Mulroney has been married to actress Catherine Keener since 1990. They met in 1987 when filming Survival Quest (1989).

Good friends with Brad Pitt.

Graduated from Northwestern University in 1985, where he attended the School of Speech.

Plays double bass and cello on the debut EP of Rain and Summer Phoenix's band, Papercranes.