The Canadian actor, 31, who played Finn Hudson in the hit TV series, was found dead at the Pacific Rim Hotel in the city centre on Saturday, said police.
The cause of death was not immediately apparent, but police have ruled out foul play. Medical examiners will conduct an autopsy on Monday.
A statement has since been released on Glee's official Twitter account, on behalf of Glee executive producers, 20th Century Fox Television and FOX Broadcasting Company, saying: "We are deeply saddened by this tragic news.
"Cory was an exceptional talent and an even more exceptional person. He was a true joy to work with and we will all miss him tremendously.
"Our thoughts and prayers are with his family and loved ones."
We are deeply saddened by this tragic news. Cory was an exceptional talent and an even more exceptional person.— GLEE (@GLEEonFOX) July 14, 2013
Cory, who had been in the musical comedy since its 2009 start, was treated for drug addiction in April and had a history of substance-abuse.
His body was found by Pacific Rim staff after he missed his check-out time on Saturday (July 13), said Vancouver's Deputy Police Chief Doug Lepard.
A statement read: "Shortly after noon today, the Vancouver Police received a call from the BC Ambulance Service regarding a sudden death in a room on the 21st floor of the Fairmont Pacific Rim Hotel at 1038 Canada Place in downtown Vancouver.
"The deceased has been identified as 31-year-old actor Cory Monteith, who achieved great fame on the popular TV series Glee."
Cory had returned to his room alone early on Saturday morning having been out with friends earlier in the evening.
He had been treated for drug abuse and was open about his battle against addiction, telling one interviewer he had taken "anything and everything".
Girlfriend and Glee co-star Lea Michele said she loved and supported her long-term boyfriend and was proud he was seeking help when he entered a rehabilitation programme earlier this year.