Gontier was born in Peterborough, Ontario, Canada, in May 1978. He grew up in Markham, Ontario. After Adam's parents divorced, he later moved to the Peterborough area, where he initially attended the Adam Scott Collegiate Vocational Institute. In 1995, he moved to the Norwood area, and attended Norwood District High School, where he met and befriended Three Days Grace members Neil Sanderson and Brad Walst
