Monteith was born in Calgary, Alberta, on May 11, 1982,[1] the younger son of Ann McGregor, an interior decorator, and Joe Monteith, a military man who served in the Princess Patricia's Canadian Light Infantry.[2][3] He had an older brother named Shaun. Monteith's parents divorced when he was seven years old,[4] and he and his older brother were raised by their mother in Victoria, British Columbia.[5] After the divorce he saw little of his father due to Joe Monteith's military service, and he had social difficulties at school. From age 13, he used alcohol and marijuana and started being truant from school.[6]
After attending 16 schools,[7] including alternative programs for troubled teens, he dropped out altogether at age 16. By that time, his drug and alcohol dependency had increased and Monteith turned to petty crimes, such as stealing money from friends and family, to fund his addictions.[5] The turning point in Monteith's life came when his mother and a group of friends staged an intervention when he was 19, and he began attending a rehabilitation program.[5] Monteith stated, "I'm lucky on so many counts. I'm lucky to be alive."[8] He eventually received his high school diploma in 2011 from an alternative school he attended in his youth in Victoria.[6]