Pele deLappe was born in San Francisco on May 4, 1916 to Wesley and Dorothy Sheldon deLappe. In her teens, she studied art in San Francisco and in New York, where she befriended Frida Kahlo and Diego Rivera during his composition of the controversial Rockefeller Center mural. When she returned to San Francisco in 1934, she became active in the San Francisco Maritime Strike as a member of the Women's Auxiliary. In addition to picketing and raising money, deLappe contributed political cartoons to Fo'csle Head, the newsletter of the Maritime Workers Industrial Union, and The Waterfront Worker, the rank and file longshore newsletter. She joined the Communist Party in 1934.

deLappe continued to be active in the labor movement and to contribute her artistic skill to various political movements throughout her life. She worked as a journalist, editor, and political cartoonist for various publications, including People's World, Daily Worker, Marine Cooks and Stewards Voice, San Francisco Chronicle, San Francisco Magazine, and The Beacon. In the 1940s, she taught life drawing at the California Labor School. In 1952, she and several other artists affiliated with the Labor School founded the Graphic Arts Workshop, a cooperative of class-conscious artists working in the spirit of Diego Rivera and his call to produce socially necessary art for the masses. During the course of her friendship with Jessica Mitford, she provided illustrations for two of Mitford's works: a pamphlet entitled "Lifeitselfmanship" and the book, Hons and Rebels. deLappe participated in group and one-person art shows throughout her life. A number of her lithographs are now a part of permanent art collections, including those of the Woodstock Artists Association in New York and the Achenbach Foundation for Graphic Art at the California Palace of the Legion of Honor in San Francisco.

deLappe was married to attorney Bert Edises in 1934. She gave birth to a daughter, Nina, in 1940 and to a son, Peter, in 1945. deLappe and Edises divorced in 1949; she re-married in 1953 to Steve Murdock, the political writer for the People's World; they divorced in 1969. She and fellow artist Byron Randall shared a close friendship from 1990 until his death in 1999. deLappe published her autobiography, Pele: A Passionate Journey Through Art and the Red Press, in 2000. deLappe died in 2007, in Petaluma, California.