He recently starred opposite Chris Farley and David Spade in the hit comedy "Tommy Boy," and co-starred with Robert Duvall in "The Stars Fell on Henrietta."

Dennehy is a familiar face on television, having starred in several television movies based on the real-life police detective Jack Reed. Dennehy made his debut as a co-writer/director on the third installment of the popular NBC movies, "Jack Reed: A Search For Justice," on which he also functioned as co-executive producer. He served in the same capacities on "Jack Reed: One of Our Own." Dennehy also co-wrote, directed and starred in the NBC telefilm "Shadow of a Doubt," with Bonnie Bedelia and Faruiza Balk. The latter two movies ranked in the top ten for NBC for the 1995-96 season.

Other movies for television in which he starred include "Leave of Absence," with Jacqueline Bisset and Blythe Danner; the TNT production "Foreign Affairs," opposite Joanne Woodward, for which he won an ACE Award for Best Actor; "Killing in a Small Town," which earned him an Emmy nomination; the mini-series "The Jackie Presser Story," for HBO; and the mini-series "To Catch A Killer," in which he portrayed serial killer John Wayne Gacy. His chilling performance garnered an Emmy nomination and an American Television Award. He received Emmy nominations for his work in the mini-series "The Burden of Proof" and for his performance in "Murder In The Heartland."

Dennehy returns often to his first love: the theatre. He has starred in "Galileo," at the Goodman Theater in Chicago; "The Rat in the Skull," at Chicago's Wisdom Bridge; the Long Wharf Theater production of "The Front Page"; "Says I, Says He," at Los Angeles' Mark Taper Forum; "The Cherry Orchard," at the Brooklyn Academy of Music; and "The Iceman Cometh," with the Goodman Theater and Dublin's famed Abbey Theater. He recently performed "Touch of the Poet" at the Goodman Theatre.

Dennehy was born in Bridgeport, Connecticut and raised in Brooklyn. He attended Columbia University on a football scholarship and graduated with a BA in history. He subsequently served five years with the Marine Corps in Vietnam and, following his honorable discharge, he pursued acting in New York City.