The actor/singer, who plays student Blaine Anderson on the musical series, is the latest star to back the Trevor Project, a crisis intervention service for lesbian, gay, bisexual, and transgender youth.
He is set to perform at the annual Trevor NextGen in New York next month (04Nov11) and insists he's delighted to be involved with the foundation.
Criss tells Variety.com, "After gaining the incredible platform from Glee, it wasn't so much of a decision to get involved as it was an opportunity to take part. I'll be honest, I'm not so much into the idea of one cause being more important than another; however, I felt that the Trevor Project was a perfect fit for my efforts.
"It stands for a lot of things that I believe in, as well as falls in line with much of what Glee stands for."
Criss' Glee co-star Kevin McHale, actress Anne Hathaway and Harry Potter's Daniel Radcliffe are among the stars who have also joined forces with the Trevor Project.