RIP GLEE STAR Cory Monteith Found Dead !

According to TMZ.com

Cory Monteith -- who famously played Finn Hudson on the TV show "Glee" -- died earlier today in Vancouver ... TMZ has learned.

According to police in Vancouver the actor was found dead in his room at the Fairmont Pacific Rim Hotel around noon today after staffers went to check on him when he didn't check out on time.

We're told he was "clearly deceased" when police arrived on the scene.

Cops say he was in the room last night with some friends before the group hit the town ... and he came back early this morning alone.

No foul play is suspected ... and cops say "it was not immediately apparent" what caused his death. An autopsy is scheduled for Monday.

Monteith voluntarily checked himself into a treatment center back in April, admitting he had substance abuse issues.  It was his second time in treatment.

Cory was 31.

A rep for the actor says they are "in shock and mourning this tragic loss."