He played George Oscar Bluth II ("G.O.B.") in the Fox series Arrested Development and Devon Banks in the NBC series 30 Rock, for which he earned a combined five Emmy Award nominations. He also appeared in the IFC series The Increasingly Poor Decisions of Todd Margaret, the NBC series Up All Night, and in the CBS series The Millers, and in films, such as Monster-in-Law, Semi-Pro, Blades of Glory, RV, Hot Rod, Let's Go to Prison, The Brothers Solomon and Teenage Mutant Ninja Turtles. Arnett also voiced the titular character of Netflix's original animated series BoJack Horseman.