A Chicago native who entered the world of performance at the age of seven, O'Leary completed his secondary education at Highland Park High School before pursuing formal studies in acting at Illinois State University and later earning a Master of Fine Arts from the University of Washington's Professional Actor Training Program in 1982. His early stage work culminated in a Broadway debut in 1986, sh… Read more
Biography written by WatchMoods, based on public sources
Known for Terminator 3: Rise of the Machines 2003 The X-Files 1993 Shameless 2011 NCIS 2003 Series ★ 8.4 The X-Files 1993
Gas Station Man Series ★ 8.3 The West Wing 1999
Fish and Wildlife Deputy Series ★ 8.2 Shameless 2011
Sgt. Rucker Series ★ 8.1 Kamen Rider: Dragon Knight 2009
Xaviax Series ★ 7.9 Bosch 2015
Vincent Ackles Series ★ 7.9 Rizzoli & Isles 2010
Worster Series ★ 7.8 24 2001
Sid Paulson Series ★ 7.8 Sabrina, the Teenage Witch 1996
Policeman (uncredited) Series ★ 7.7 CSI: Miami 2002
Stewart Otis Series ★ 7.6 NCIS 2003
Martin Freydano Series ★ 7.5 NCIS: Los Angeles 2009
Harry Zinetti Series ★ 7.5 Murder, She Wrote 1984
Hank Duncan Series ★ 7.4 Home Improvement 1991
Marty Taylor Series ★ 7.4 Miami Vice 1984
Scotty Series ★ 7.2 Without a Trace 2002
Carey Chase Series ★ 7.2 Chicago Hope 1994
Mr. Loey Series ★ 7 Numb3rs 2005
Roland Haldane Series ★ 7 The Guardian 2001
Brad Fulton Series ★ 7 Matlock 1986
Paul McBride Series ★ 6.9 Big Love 2006
Ronny Series ★ 6.9 The District 2000
Don Hardin Series ★ 6.8 Law & Order: LA 2010
Joe Laight ★ 6.6 Hot Shots! 1991
Pete 'Dead Meat' Thompson ★ 6.6 Bull Durham 1988
Jimmy ★ 6.5 Walker 1987
James Walker ★ 6.3 Mad City 1997
CTN Junior Executive ★ 6.2 Terminator 3: Rise of the Machines 2003
Mr. Smith Series ★ 6.2 Tremors 2003
George Meadows ★ 6 Project: ALF 1996
Capt. Rick Mullican ★ 5.8 The Enemy Within 1994
Lt. William Dorsett ★ 5.7 Miss Congeniality 2: Armed and Fabulous 2005
Agent Jenkins ★ 5.5 Candyman: Farewell to the Flesh 1995
Ethan Tarrant 
