Ruthie Tompson was born on July 22, 1910 in Portland, Maine and raised in Boston, Massachusetts. She then moved with her family to Oakland, California in November 1918 at age eight. In 1924, her parents divorced and her mother, Arlene, remarried artist John Roberts. The family relocated to Los Angeles and their house was in the same block as the house of Robert Disney, uncle of Walt Disney. This is where Roy and Walt Disney lived when they first came to Los Angeles.

As she stated in an interview, Tompson first met the Disneys when she visited her neighbor Robert’s new baby.The location of The Walt Disney Company, then known as the Disney Brothers Cartoon Studio, was not far from her home – she passed it on her way to grammar school. She was invited into the office after many times of standing outside and watching them work through the window. She visited the office often and ended up appearing in the Alice Comedies.
At the age of 18, Tompson started working at Dubrock’s Riding Academy, where Roy and Walt Disney often played polo. Walt Disney remembered Tompson from when she was young and offered her a job as an inker and scene planner. She helped with Disney’s Snow White and the Seven Dwarfs. Not long after she was hired, Tompson was promoted to the final checker position where she reviewed animation cels before they were photographed onto film. In 1948, Tompson was promoted to animation checker and scene planner. She became one of the first three women admitted into the International Photographers Union, Local 659 of the IATSE.

Tompson retired in 1975 after working for The Walt Disney Company for almost 40 years. As of 2016 she works for an in-house television channel at the Motion Picture & Television Fund (MPTF) Country House. Tompson is the oldest member of Women in Animation.