Julius M. Simmons was an American chemist. He worked as a research assistant at the Metallurgical Laboratory in Chicago during the Manhattan Project. His first wife, Louella, also worked on the Manhattan Project.
Simmons served as an assistant director of the metallurgy division of the Argonne National Laboratory from 1951 until 1957. He then moved to the D.C. area to work for the Atomic Energy Commission (AEC).
At the AEC, Simmons coordinated U.S. bilateral exchange agreements with Great Britain and Japan. He later served as Chief of the Fuels and Materials Branch of the Reactor Division at the AEC.
Simmons died on January 22, 1987 in Rockville, MD.