Jill Hennessey graduated from the Grand River Collegiate Institute in Kitchener, Ontario. She made her acting debut in the 1988 film Dead Ringers, alongside her sister Jacqueline Hennessy. Her first major break was on NBC's Law & Order: she played ADA Claire Kincaid from 1993 to 1996.
Hennessy's most important role was in the NBC series Crossing Jordan, where she played medical examiner Jordan Cavanaugh. The role also led to several crossover appearances in another NBC series, Las Vegas. The series was cancelled in 2007.
She also starred in several independent films such as The Acting Class and Small Town Murder Songs, as well as mainstream releases such as Wild Hogs. She also appeared on Broadway, and has recorded an album, Ghost in My Head, in 2009.
- Hennessey was considered for the role of Dana Scully in Fox's hit The X Files, only to be replaced by Gillian Anderson.
- Golden Satellite Award, Best Performance by an Actress in a Miniseries or a Motion Picture Made for Television, 2001 (for Nuremberg)
- Gracie Allen Award, Outstanding Lead Female in a Drama Series, 2007 (for Crossing Jordan)
FILM:
- Dead Ringers (1988)
- RoboCop 3 (1993)
- Trip nach Tunis (1993)
- The Paper (1994)
- I Shot Andy Warhol (1996)
- Kiss & Tell (1996)
- A Smile Like Yours (1997)
- Most Wanted (1997)
- Weekend Getaway (1998)
- Dead Broke (1998)
- The Florentine (1999)
- Row Your Boat (1999)
- Two Ninas (1999)
- Chutney Popcorn (1999)
- Molly (1999)
- Komodo (1999)
- The Acting Class (2000)
- Autumn in New York (2000)
- Exit Wounds (2001)
- Love in the Time of Money (2002)
- Pipe Dream (2002)
- Wild Hogs (2007)
- Game of Life (2007)
- Lymelife (2008)
- Small Town Murder Songs (2010)
- Roadie (2011)
TELEVISION:
- Law & Order (regular, 1993-1996)
- Crossing Jordan (regular, 2001-2007)
- Las Vegas (recurring, 2004-2006)
- Luck (recurring, 2012-preset)