In addition to his achievements as an animator and directing animator, Johnston (in collaboration with his lifelong friend and colleague Frank Thomas) authored four landmark books: Disney Animation: The Illusion of Life, Too Funny for Words, Bambi: The Story and the Film, and The Disney Villain.

Johnston and Thomas were also the title subjects of a heartfelt 1995 feature-length documentary entitled Frank and Ollie, written and directed by Frank's son, Theodore (Ted) Thomas.

In November 2005, Johnston became the first animator to be honored with the National Medal of Arts at a White House ceremony.

The Walt Disney Company director emeritus Roy E.Disney said, "Johnston was part of an amazing generation of artists, one of the real pioneers of our art, one of the major participants in the blossoming of animation into the art form we know today. One of Ollie's strongest beliefs was that his characters should think first, then act ... and they all did. He brought warmth and wit and sly humor and a wonderful gentleness to every character he animated. He brought all those same qualities to his life, and to all of our lives who knew him. We will miss him greatly, but we were all enormously enriched by him."

At Disney, Johnston's first assignment was as an in-betweener on the cartoon short "Mickey's Garden." The following year, he was promoted to apprentice animator, where he worked under Fred Moore on such cartoon shorts as "Pluto's Judgement Day" and "Mickey's Rival."

Johnston got his first crack at animating on a feature film with Snow White and the Seven Dwarfs. Following that, he worked on Pinocchio and virtually every one of Disney's animated classics that followed. One of his proudest accomplishments was on the 1942 feature Bambi, which pushed the art form to new heights in portraying animal realism. Johnston was one of the four supervising animators to work on that film.