Five foot eight, Jill Hennessy was born in Edmonton, Alberta, Canada on November 25, 1969, Only three minutes after her Twin sister Jacqueline Hennessy. (They were nicknamed Jaq & Jill) Jill and Jacqueline played twin sisters in Dead Ringers in 1988. When Jill was thirteen, her parents separated. In school, Jill won all kinds of awards, Best Music Student among them. She plays guitar and has an amazing voice. At fifteen, she began modeling in Toronto. Her grandmother would drive her all over town. Although she had considered pursuing the scholastic route like Jacq had decided to do, she knew she had to try acting or she'd regret it. So at seventeen, she moved to Toronto, choosing to by-pass Grade 13 in favor of acting.

Facts:
Jill speaks Italian, French and Spanish. She is also fluent in German.
She has Irish, Italian, Swedish, French and Ukrainian ancestry.
"The Ballad of Jill Hennessy" by Mollycuddle is named after her.
She graduated from Kitchener, Ontario, Canada's Grand River Collegiate (high school).
She loves to cook, and opened Hennessy's Tavern in Northvale, NJ in 1999. The Tavern serves "comfort food." Loves riding motorcycles with her husband. Jill's father, John, was a meat salesman, which required considerable travel and resulted in frequent moves. Her mother, Maxine, left the family when Jill was small. She also has a younger brother, John Jr. She is described by Miguel Ferrer as being a non-angry version of her Crossing Jordan character Jordan Cavanaugh. She was voted one of the "Fun and Fearless Females" by Cosmopolitan Magazine. She had a second marriage ceremony to Paolo Mastropietro, Her husband since October 1, 2000 in January 2001 at New York City Hall with Rudolph Giuliani officiating. She is sometimes credited as Jillian Hennessy.

Jill & Paolo had their first child, baby boy Marco Mastropietro in the Fall of 2003.