Mary Elting Folsom (June 21, 1906 - January 29, 2005) was a prolific American author best known for her contributions to children's literature.
After graduating from the University of Colorado at Boulder she moved to New York City where she worked as a magazine editor and an author of children's books. She was married to writer Franklin Folsom; her son is the writer Michael Folsom.
Mary Elting also wrote under the name Campbell Tatham.