[3][4] Sito first began studying animation while attending cartooning classes at the High School of Art and Design.

Additionally, Sito studied life drawing at The Art Students League of New York under Robert Beverly Hale.

[5] Sito assisted retired Disney animator Shamus Culhane on one of his final projects, a 1977 education short entitled Protection in the Nuclear Age.

Sito's first big break came in 1976 when he was hired by legendary animation director Richard Williams to work on his film Raggedy Ann & Andy: A Musical Adventure.

Returning to Los Angeles in 1988, Sito became a mainstay of the Disney Feature Animation division, contributing to the classic films The Little Mermaid, Beauty and the Beast,[12] Aladdin, The Lion King, Pocahontas, Fantasia 2000, and Dinosaur.

He was the storyboard director of the first Shrek film and he was president of the Motion Picture Screen Cartoonist's Local 839 (later renamed The Animation Guild, I.A.T.S.E.

[15] Tom Sito was interviewed for the PBS American Experience documentary "Walt Disney" (2014) for WGBH Boston.

[16] In July 2017, Tom Sito was elected by his peers to the Board of Governors of The Motion Picture Academy of Arts and Sciences to represent the Short Films and Feature Animation Branch 2017-2020.