Allison Janney, Keegan-Michael Key, Debra Messing, Jordan Peele, Octavia Spencer and Sofia Vergara have also been added to the lineup, reported CBS News online.
They join Matthew McConaughey, Woody Harrelson, Bryan Cranston, Julia Louis-Dreyfus, Julianna Margulies, Jim Parsons, Amy Poehler, Julia Roberts, Kerry Washington, Halle Berry, Zooey Deschanel, Adam Levine and Gwen Stefani.
'Game of Thrones' picked up the most Emmy nominations this year, winning a total of 19 nods, and will battle it out for the title of Outstanding Drama Series with 'Breaking Bad', 'Downton Abbey', 'House of Cards', 'Mad Men' and 'True Detective'.
Seth Meyers will host the main event, to be broadcast on NBC on August 25.