The Glee star, and former Vancouver resident, is calling on the city's mayor Gregor Robertson to support a campaign to save the historic Waldorf Hotel, which also doubles as a recording studio and an art gallery.
The newly-restored building stands on plot of land which has been bought by developers with plans to turn the site into condominiums.
Monteith took to his Twitter.com page on Sunday (13Jan13) to tell fans about the campaign and he provided a link to the petition, encouraging his followers to get involved.
He writes, "The Waldorf Hotel, a cultural bastion for the city of Vancouver, is in imminent danger of being turned into condos. Sign the petition!... I know everyone is watching the (Golden) globes, but this place is really special and Vancouver has enough condominiums."