William Devane is an American film, television, and theatre actor, best known as Gregory Sumner on CBS’ Knots Landing and James Heller on FOX’s 24. Other television credits include Dean Sanderson Sr. on FOX’s The Grinder, President Henry Hayes on Syfy’s Stargate SG-1, and Bernie Hobson on CBS’ Early Edition.

Film credits include Space Cowboys, Marathon Man, and McCabe & Mrs. Miller.

Theatre credits include his Broadway debut as Motherball in The Freaking Out of Stephanie Blake (Eugene O’Neill Theatre), Chester Lee in The Chinese and Dr. Fish (Ethel Barrymore Theatre), and Sonny in The Watering Place (Music Box Theatre); and Off-Broadway, as Iachimo in The Tale of Cymbeline, Gregory/Others in Romeo and Juliet, and Gaoler/Others in The Winter’s Tale (Delacorte Theatre), Randle Patrick McMurphy in One Flew Over the Cuckoo’s Nest (Mercer Arts Center), Ranchman in The People vs. Ranchman (Fortune Theatre), and Robert Ken O’Dunc in MacBird! (Village Gate).