Leo E. Simons, 64, a retired investigator of the Air Force, died Sunday at Holy Cross Hospital in Silver Spring. He had had cancer.

Mr. Simons was born in Milwaukee. He came to Washington in the 1930s and began his government career as a clerk in the Justice Department. In 1940, he became an adjudicator and claims examiner for the old Social Security Board.

During World War II, he was an investigator in the Army counterintelligence corps and saw service in the Pacific. He later joined the Veterans Administration as a claims investigator. he joined OSI in 1956 and remained with it until his retirement in 1969, at which time he received a certificate of service from the Air Force.

Mr. Simons also was an officer in the Air Force Reserve. He retired in 1974 with the rank of lieutenant colonel.

Apart from his government work, he was active in Osteogenesis Imperfecta, National Capital Area, Inc. It is an organization devoted to the study and cure of genetic bone disorders. Mr. Simons was its vice president at the time of his death.

He also was a member of St. Camillus Parish in Silver Spring and had been active in its Holy Name Society.

Survivors include his wife, Camille, of the home in Silver Spring; a son, Patrick, of Arlington, Tex.; a daughter, Kathleen Stein, of Silver Spring, and two grandchildren.