Dillon grew up in Kingston, Ontario, where he was born and raised. Dillon was a student at the Kingston Collegiate and Vocational Institute at the same time as David Usher and members of The Tragically Hip like Gord Downie. Dillon attended Queen's University and resided in London, England after high school before going to Toronto and then Los Angeles.
Headstones' Dillon is the band's lead singer. The band formed in 1987 and released their debut album Picture of Health in 1993, which included the hits "When Something Stands For Nothing," "Cemetery," "Tweeter and the Monkey Man," and "Three Angels."
In filmmaker Bruce McDonald's 1995 picture Dance Me Outside, Dillon made his big screen debut. He subsequently starred as Joe Dick in Hard Core Logo, a 1996 feature film directed by McDonald.