William Opal Roberts was born on August 2, 1899. In 1922 his family made the move from Kentucky to California. Roberts worked in New York as an illustrator for a while. He joined the Disney Studios in 1932 where he did a lot of work on Pluto. He began working on Snow White and the Seven Dwarfs primarily working on the dwarfs. You can see his work when the Doc leads the group to the house ever so cautiously after noticing the lights one, the dwarfs working at the mine and discovering the Queen got Snow White, and the chase scene that follows. He also worked on scenes that hit the cutting room floor.
Milt Khal worked as Roberts assistant, thus Roberts was one of the inspirational people that helped train the nine old men. Khal recalled working under Roberts and his very different style of animation: he referred to Roberts as one of the fast-action boys.
He earned the role of director and directed some of the sequences in Pinocchio, Fantasia, Dumbo, and Bambi.
He left the animation business in the 1940's. Roberts died in 1974.