Kansas artist and art therapist Mary Huntoon was born Mary Huntoon Atkinson in 1896, in Topeka, Kansas. She was the daughter of Ruth Huntoon Atkinson and Franklin Henry Atkinson and the descendent of prominent Topeka pioneer Joel Huntoon. Mary Huntoon spent 6 years of her childhood on the cattle ranch of her grandfather, Fred Huntoon, in Beaver County (No Man's Land), Oklahoma. At age twelve, she was rechristened Mary Huntoon Parsons and adopted by her mother's second husband, Harvey Greely Parsons.

Huntoon studied art under Kansan artist George Stone and other instructors at Washburn University. After graduating from Washburn in 1920, Huntoon moved to New York City where she studied at the Art Students League. Among her instructors there were Joseph Pennell, Robert Henri, and George Bridgeman. In 1921, Huntoon received an assignment to do a series of etchings in Paris. She lived and studied in Paris and Corsica from 1921-1931. Huntoon's first one-artist show was in Paris at the Galerie Sacre du Printemps in 1929.

Huntoon returned to Topeka in 1931, where she lived until her death in 1970. She took part in many notable activities during these four decades. Among these were assuming the directorship of the Federal Art Project in Kansas (1934-1938), assisting in the establishment of the Department of Art, Physical Medicine and Rehabilitation at Winter Veterans Administration Hospital (1946-1959), and serving as director of Studio Gallery, Inc. (1961-1962). Huntoon carried out research in art therapy while she was employed at Winter V.A. Hospital and wrote and published several articles on the subject. She contributed art work to many exhibitions, won numerous awards, and has paintings and etchings permanently displayed in the Topeka Public Library, Washburn University, the Salina Art Association, the Philadelphia Art Museum, and numerous public buildings across Kansas.

Huntoon was married to Charles Hoyt (1920-29), Lester Hull (1933-37), Erwin Seaman (1945-1956) and Willis McEntarfar (1957-70).