Ralph Clarence Johnson, 74, a retired Navy rear admiral who commanded a destroyer in the Atlantic and the Mediterranean in World War II and who later helped found the Navy's officer candidate school at Newport, R.I., died Nov. 17 at the Veterans Administration Hospital at Perry Point, Md. He had had a series of strokes.

Adm. Johnson, a resident of Annapolis, was born in Galesburg, Ill. He graduated from the U.S. Naval Academy in 1932.

During the war, he commanded the destroyer Cowie in support of the allied landings in North Africa at the end of 1942 and in Sicily in 1943. Near the end of the war he was gunnery officer on the staff of the commander of destroyers for the Atlantic fleet.

Subsequent assignments included the Armed Forces Staff College, where the future admiral graduated. In 1951, he was sent to Newport, R.I. As commanding officer of the Naval Schools Command there he helped organize its OCS program. He served in that post for three years.

Adm. Johnson later was deputy inspector of the Navy, chief of the Naval mission to Turkey, and commander of the field command of the Defense Atomic Support Agency. He was commanding officer of the Southern Command with headquarters in the Panama Canal Zone when he retired.

After leaving the Navy Adm. Johnson settled in Annapolis. He was associated with the stock brokerage firm of Clark-Melvin in Annapolis until he retired in 1984.

His military decorations include the Bronze Star and the Legion of Merit.

He was a member of the Naval Academy Alumni Association, the Naval Academy Golf Club, and the Annapolis Yacht Club.

His first wife, the former Ethel Soule, whom he married in 1933, died in 1969.

Survivors include his wife, Weslia Stafford Johnson of Annapolis; three children by his first marriage, Carol Reavis of Glen Arm, Md., Sara Buettner of La Jolla, Calif., and David Johnson of Arlington; three stepchildren, Robert Kelley of Telluride, Colo., Dr. David Kelley of Rochester, Minn., and Gail Adshead of Cumberland, Maine; one sister, Florence O. Johnson of Galesburg; 12 grandchildren, and one great-grandchild.