Isadore Ellis (1910–1994), credited as I. Ellis and known throughout the animation industry as Izzy Ellis, was an American animator best known for working for Warner Bros. Cartoons under the Bob Clampett & Frank Tashlin units. Ellis had a long career in the animation industry, which started at Ub Iwerks Studio in 1935. After three years, Ellis moved to Leon Schlesinger Productions, where he worked under the Clampett B/W unit, under the Ray Katz management. Ellis continued to animate in the B/W unit under the supervision of Norman McCabe, and eventually Frank Tashlin. Ellis reunited with Clampett after Robert McKimson took over Tashlin's unit. However, Ellis relocated to McKimson's unit after Art Davis took over the Clampett unit. In 1948, Ellis left to do commercial work.
In the 1960s, Ellis started working for three different animation studios. He spent seven years, from 1960 to 1967, working for Paramount Cartoon Studios. He briefly worked for Krantz Films but moved to Hanna-Barbera Productions in 1968, where he would spend the next ten years animating.