Mary Blair was born Mary Browne Robinson on October 21, 1911 in McAlester, Oklahoma. In the 1920s, her family eventually settled near San Jose, California. Although her family suffered from great poverty during the depression, it did not stop Mary from giving the valediction at her high school graduation nor did it stop her from gaining attention for her artistic ability. She soon received a scholarship to the Chouinard school of art in Los Angeles, one of the best art schools of the time.

During her stay at Chouinard, she studied under artists such as illustrator Pruett Carter and Chouinard master composition teacher Lawrence Murphy. In 1931, she was selected to assist David Alfaro Siqueiros to create a fresco mural for the school courtyard. It was also at Chouinard that she met her future husband, Lee Everett Blair. The two graduated in 1933 and were eventually married on March 3, 1934. The job market in the art industry was bleak during the Great Depression and the two were separated for a short period when Mary had to stay with her parents while Lee worked at Ub Iwerk's animation studio on the Flip the Frog shorts. Mary then took work as a barmaid until Lee got her work as a cell painter at the Iwerks studio.

From the "Baia" sequence in The Three Caballeros (1945)