Michael Wincott
From Halopedia, the Halo wiki
Template:RealworldMichael Wincott is a Canadian actor best known for his deep, gravelly voice.
Born on January 21, 1958, in Toronto, Ontario, Canada, Wincott was raised in Scarborough, Canada which is a suburb of Toronto. He graduated from Juilliard Drama School in 1986.
Wincott is most identifiable playing either small, character roles in indie films or villains in more mainstream fare. His most recognizable role was the evil crime lord Top Dollar in 1994's The Crow.
He contrubited his voice to Halo 2 as the High Prophet of Truth. It is very likely that he will return to reprise his role in Halo 3.