Justin Long and Kristen Bell will lend their voices to the show currently titled 'Unsupervised,' which focuses on two optimistic teenagers, Gary and Joel, who are "navigating the harsh landscape of teenage life and trying to do what's right without any parental guidance whatsoever."
Fred Armisen, Romany Malco, Alexa Vega and 'Sunny' star Kaitlin Olson will also voice characters in the show, as will Rosell and Hornsby.
The series will premiere in January and run after the FX animated series 'Archer.' It will also be animated by the 'Archer' production team.
"Having worked with David, Rob and Scott for many years on 'Sunny,' it gives us great pleasure to see them make their own stamp on FX," Nick Grad, executive vice president of original series at FX, said in a statement. "'Unsupervised' is a great addition to our comedy roster and, like all of our comedies, it's smart and really funny."