Walt Otto was born in Horicon, Wisconsin. A correspondence course in art was followed by a brief stint as a studio photographer in Oshkosh before joining the Army Air Corps during World War I. After the war, he moved to Chicago and took classes at Chicago Academy of Art and the Art Institute of Chicago. Otto once again joined the military during World War II, where he put his skills to use as an aerial photographer.
Throughout his career, Otto provided photography and illustrations for a variety of advertisers, including Shell and Kellogg. His illustrations — all featuring sporty women — appeared on three Saturday Evening Post covers between 1935 and 1940.