"SNL!!!!I can't even pretend to hide my excitement about this haha! This is something truly special and I am extremely grateful for the opportunity from Lorne and everyone involved at @nbcsnl New York City let's have some fun!!!" Watt tweeted Tuesday.
The musical guest for the episode will be country star Luke Combs.
Oscar nominee Adam Driver is hosting Saturday's episode. He is the star of The Report, Marriage Story and Star Wars: The Rise of Skywalker. Halsey will perform.