Chris Colfer, Kevin McHale, Cory Monteith and Mark Salling will join the pop star for the 12th annual award show honoring the hottest in film, television, music, sports and fashion, as voted by teens.
Glee has received 13 Teen Choice Awards nominations.
Taylor Lautner, Jane Lynch, Channing Tatum, Ellen DeGeneres, Josh Hutcherson, Cat Deeley, Keke Palmer and the cast of Big Time Rush will also appear on the show. Previously announced participants include Zachary Levi, Zac Efron, Ashley Greene, Jim Parsons, Robert Pattinson and the Kardashian sisters.
The Teen Choice Awards airs Monday, Aug. 9 at 8/7c on Fox.