He is known for his role as Greg Sumner on the primetime soap opera Knots Landing (1983–1993)[1] and as James Heller on the Fox serial dramas 24 (2001–2010) and 24: Live Another Day (2014).

[4] Devane graduated from Philip Schuyler High School in Albany, and then the American Academy of Dramatic Arts in New York City in 1962.

Devane is widely known for his ten years as the ambitious and hardnosed politician-turned-corporate titan Greg Sumner on Knots Landing.

[5][6] In 1994, Devane appeared as Al Capone in Lois & Clark: The New Adventures of Superman in an episode entitled "That Old Gang of Mine".

Devane appeared in the films McCabe & Mrs. Miller (1971); Lady Liberty (1971); Family Plot (1976), directed by Alfred Hitchcock; Marathon Man (1976); Rolling Thunder (1977); Yanks (1979); Testament (1983) with Jane Alexander; Timestalkers (1987) with Lauren Hutton and Klaus Kinski; Forgotten Sins (1996) with John Shea; Exception to the Rule (1997); Payback (1999); Hollow Man (2000) and Space Cowboys (2000).

In 2008, he appeared in Russ Emanuel's Chasing the Green alongside Jeremy London, Ryan Hurst, and Robert Picardo.