Equally adept at comedy and drama, this Boston-bred actress honed her skills on the New York stage before seeking screen work in Los Angeles. Although she appeared in supporting film roles over the years, usually as the wise woman who didn't get the guy (Primal Fear, Forces of Nature), she excelled on TV. After a few failed pilots, Tierney came to prominence as a witty writer on NBC's NewsRadio. When the sitcom ended in 1999, she quickly signed on to ER as a bright but brooding med student, an intensely serious role that earned her an Emmy nod in 2001. With steady small-screen employment, Tierney took chances on a number of indie films, including a contemporary adaptation of Macbeth titled Scotland, Pa. that was written and directed by then-husband Billy Morrissette. The flick tanked at the box office and, unfortunately, so did their relationship; the couple filed for divorce in 2006, after 13 years of marriage. In 2009, she filmed the pilot for the NBC dramedy Parenthood, but pulled out of the project to undergo surgery and treatment for breast cancer (Lauren Graham replaced her in the role). Following her recovery, she returned to acting in the stage production North Atlantic opposite Frances McDormand and reprised her recurring role as Dennis Leary's love interest on Rescue Me.
- Caught the acting bug after competing in a high-school drama festival.
- Her father, Joseph, was a long-time Boston City Council president and a mayoral candidate.
- Named the champion of Bravo's 2004 Celebrity Poker Showdown, a show hosted by NewsRadio costar Dave Foley.
- Became an ordained minister and officiated at ER castmate Parminder Nagra's 2009 wedding.
- 2016, Emmy — Outstanding Supporting Actress in a Drama Series: Nominee
- 2016, Critics' Choice Awards — Best Supporting Actress in a Drama Series: Nominee
- 2001, Emmy — Outstanding Supporting Actress in a Drama Series: Nominee
- 2000, Screen Actors Guild Awards — Outstanding Performance by an Ensemble in a Drama Series: Nominee
- 2016, Golden Globe — Best Performance by an Actress in a Supporting Role in a Series, Limited Series or Motion Picture Made for Television: Winner
- 2015, Critics' Choice Awards — Best Supporting Actress in a Drama Series: Nominee
- Joseph Tierney Jr. — Brother
- Billy Morrissette — Ex-husband
- Pat Tierney — Mother
- Joseph Tierney — Father
- Deirdre Tierney Pulgini — Sister
- Attended New York University, New York, New York, United States
- Birth Name: Maura Lynn Tierney
- Birth Place: Boston, Massachusetts, United States
- Profession: Actor