Jack at the premiere of Rugrats Go Wild John A. "Jack" Riley Jr. (December 30, 1935 - August 19, 2016) was an American actor and comedian, best known on Nickelodeon as the voice of Stu Pickles from Rugrats and All Grown Up! "Gee, this is harder than I thought."This article is a stub. You can help Nickipedia by expanding it. Retrieved from "https://nickelodeon.fandom.com/wiki/Jack_Riley?oldid=231962" Categories: Stubs Voice actors Deceased people Rugrats cast members Film actors Actors Real persons 1930s births 2010s deaths Community content is available under CC-BY-SA unless otherwise noted.