James Allen St. John was born in 1872.  He studied at the Art Students League under, J. Carroll Beckwith, William M. Chase, and H. Siddons Mowbray, followed by the Academy Julian in Paris, under J. P. Laurens.  St. John later worked in Chicago, as well as teaching at the Chicago Art Institute and the American Academy of Art.

The artist was identified with the fiction of Edgar Rice Burroughs and other early writers of fantasy and science fiction.  Some of the publications he contributed to were Amazing Stories, Blue Book, Fantastic Adventures and Weird Tales.  St. John's "Tarzan" illustrations were published in book form as well as in magazines, and his pen and ink renderings can also be found in many book interiors.

The artist died in 1957.

J. Allen St. John; An Illustrated Bibliography by Darrell C. Richardson was published in 1991.  He was elected into the Society of Illustrator's Hall of Fame in 2000.