The 26-year-old actor, who played Anna Kendrick's love interest in last year's Pitch Perfect, will star in a March episode of the FOX show.
Darren Criss (Glee's Blaine Anderson) made the casting announcement with a photo posted to Instagram Tuesday.
"Me, @ChordOverstreet & @SkylarAstin... And a #DramaticSelfie for you all. So glad to have our buddy Skylar on #Glee!" Criss captioned the photo.
Michele told The Hollywood Reporter last year that she hoped to get Astin on the show.
We've been trying! I wanted them to see him for Brody and for so many characters along the way but he just has to stop being a movie star and doing so many movies! I'm his biggest fan, he's one of my best friends, and I couldn't be happier for him and his success. He's amazing in Pitch Perfect. The minute I can get him on Glee, I want him on the show.