Twitter has been flooded with an outpouring of support and love for the late star.
Just minutes after police confirmed Monteith's death, Mark Salling, who plays Noah "Puck" Puckerman on the show, simply tweeted, "no." That tweet was later deleted, but not before being retweeted thousands of times.
Dot Jones, who plays Coach Beiste on the show, tweeted, "I HAVE NO WORDS! MY HEART IS BROKEN CORY WAS NOT ONLY A HELL OF A FRIEND HE WAS ONE AMAZING MEN THAT I WILL HOLD CLOSE TO MY HEART FOREVER."
"Glee" guest star Kristin Chenowith tweeted, "RIP CoryMontieth. You will be loved. Always."
ABC News Radio contributed to this report.