Harth was born in Galt, Ontario, Canada. He got his first taste of acting in grade school when the drama club cast the school's largest child to play Santa in their Christmas pageant. Harth was just a kindergartner at the time. Involved in community theatre and improvisational comedy during high school, it wasn’t until he relocated to Vancouver in 1989 that he seriously pursued acting full-time. Prior to landing his first professional gig in a TV commercial for a food chain, Harth toured the semi-pro wrestling circuit in Canada's small towns and provinces as The Bible Thumper, adorned in black robes with a cross shaved on his head.