He made his acting debut in the television series Stargate Atlantis (2004), and had other roles in shows including Smallville (2005), and Supernatural (2005).
During his career, he starred in over eighteen dramas and seventeen films, with Monte Carlo (2011), Final Destination 3 (2006), and Sisters & Brothers (2011), all becoming commercially successful.
In a 2011 interview with Parade magazine, he discussed his history of substance abuse as a teen, and in March 2013, again sought treatment for his addiction.
[9] 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.
When Glee was being cast, Monteith's agent, Elena Kirschner, submitted a video of him drumming with some pencils and Tupperware containers.
He is a popular jock at the top of the school's social hierarchy, but when forced to join the glee club, he finds he loves it.
His story lines have seen him struggle with his decision to stay in the club, which is at the bottom of the social ladder, while he maintains his popular reputation and the respect of the other jocks.
The character must deal with his attraction to both head cheerleader Quinn Fabray (Dianna Agron) and glee club star singer Rachel Berry (Lea Michele) and his storylines increasingly focus on his relationship with them both.
"[21] In the second season's eighth episode, "Furt," Tim Stack of Entertainment Weekly noted "It's been a while since we've gotten some Finn focus, and I think I just missed Cory Monteith.
He'd met the band's lead singer, Justin Wilczynski on the set of MTV's short-lived show Kaya on which they both performed music together.
The band's debut single 'Maybe Tonight' is one of six tracks Monteith actively performed on and helped produce and is included on the EP, Miramar, released on February 4, 2014.
[26][27][28] In May 2010, the cast of Glee went on a two-week live tour with stops in Los Angeles, Phoenix, Chicago, and New York City.
[36][37] Canadian director Gia Milani's film All The Wrong Reasons stars Monteith as "a big box department store manager whose wife is struggling with post-traumatic stress disorder."
[40] On July 20, 2013, Ryan Murphy stated in various media outlets that Monteith was set to have a tribute in the third episode of season five, which also dealt with the death of his character Finn Hudson.
These include "If You Say So", which Michele began writing a week after his death and references the last words he said to her,[51] and "Hey You", a follow-up to "If You Say So", released in April 2017.
[57][58] Monteith was involved in a charitable organization called Project Limelight, a nonprofit performing arts group for children in the Vancouver Downtown Eastside area.
Monteith was scheduled to check out that day following a seven-night stay, but when he failed to do so, hotel staff entered his room around noon and found his body.
[64] The preliminary autopsy report stated that Monteith died from "a mixed drug toxicity" consisting of heroin and alcohol[65][66] and that his death appeared to have been accidental.
[69] Monteith's body was cremated in Vancouver on July 17, following a private viewing by his immediate family and partner Lea Michele.
[55] The season's third episode, "The Quarterback", aired on October 10, 2013, and served as a tribute to Monteith, focusing on the death of his character Finn Hudson.
"[72] The 65th Primetime Emmy Awards, held on September 22, 2013, featured an extended tribute to Monteith by his Glee co-star Jane Lynch, along with four other actors who died in 2013.
[74] On July 8, 2020, Naya Rivera, Monteith's Glee co-star and close friend, accidentally drowned, and her body was recovered on the seventh anniversary of his death.