Clay Edgar Spohn was born November 24, 1898, in San Francisco, to Lena (Schaefer) and John Henry Spohn. From 1919 to 1921, Spohn studied at the University of California at Berkeley, and from 1922 to 1924, he studied at the Art Students League in New York under Kenneth Hayes Miller, Boardman Robinson, George Luks and Guy Pene Du Bois. He also became acquainted with Alexander Calder at the Art Students League. In 1924, Spohn was employed as an assitant designer to muralist Ezra Winter. From 1926 to 1927 he studied in Paris at the Academie Modern, a school run by Fernand Leger and Orthon Fireze.
Returning to San Francisco in 1927, Spohn became an active member in the Bay Area art scene. The Treasury Department commissioned him, in 1938, to execute a mural for the Montebello, California post office, and in 1939, he completed another mural under the sponsorship of the WPA for Los Gatos Union High School in Los Gatos, California.
In 1942, the San Francisco Museum of Art mounted Spohn's solo exhibition "Fantastic War Machines and Guerragraphs", consisting of a series of drawings inspired by dreams of World War II. From 1945 until his resignation in 1950, Spohn was employed as instructor of drawing and painting at the California School of Fine Arts, where he befriended Clyfford Still and Mark Rothko. In 1949, at the California School, he organized a group exhibition entitled "The Museum of Unknown and Little Known Objects", in which Spohn's extraordinarily-constructed objects were a focal point.
Spohn moved to Taos, New Mexico in 1952, and participated in several national exhibitions. He was Visiting Lecturer at Mount Holyoke College, Massachusetts, in 1958, after which he moved to New York City where he executed a series of paintings under the sponsorship of the collector J. Patrick Lannan. From 1964 to 1969, he taught at the School of Visual Arts in New York.
After a two year move to Taos, Spohn returned to New York in 1971. In 1974, the Oakland Museum sponsored a retrospective of Spohn's work.
Clay Spohn died in New York City on December 19, 1977.