Jillian Noel "Jill" Hennessy (born November 25, 1968) is a Canadian actress and musician. She is most known for her roles on the American television series Law & Order, on which she played prosecutor Claire Kincaid for three seasons, and Crossing Jordan, in which she played the lead character, Jordan Cavanaugh, for six seasons. She has also acted in films such as RoboCop 3 and Most Wanted, and the independent films Chutney Popcorn and The Acting Class, the latter of which she also wrote and co-directed.
Hennessy was born in Edmonton, Alberta. Her father, John Hennessy, was a meat salesman and sales/marketing executive, a job that required considerable travel and resulted in frequent moves for the family. Her mother, Maxine, a secretary, left the family in 1982, leaving her daughter to be partially raised by her paternal grandmother, Eleanor, in Kitchener, Ontario.