William J. Flaherty, 61, a retired official of the Disabled American Veterans, died of cancer Thursday at the Veterans Administration Hospital here.

A disabled veteran of World War II, he was deputy national director of legislation of the DAV when he retired in May, 1976. He had held that position since 1972.

Mr. Flaherty joined the national legislative staff of DAV here in 1963. His work included promotion of federal legislation to benefit veterans.

Earlier, he had worked for 17 years as a veterans claims representative with the DAV and with the American Veterans of World War II, Korea and Vietnam (AMVETS) in Minneapolic and with the American Legion in Philadelphia.

Born in Philadelphia, Mr. Flaherty enlisted in the Army in 1942. During World War II, he served in Europe as a tank commander under then Lt. Col. Creighton W. Abrams Jr., whose battalion led the breakthrough out of Normandy, released Americans from Besieged Bastogne and dashed to the Rhine.

Wounded in action in the Battle of the Bulge, Mr. Flaherty was medically discharged with the rank of sergeant in 1945.

He came to Washington, where he earned a degree from American University under a DAV program.

Mr. Flaherty lived in Silver Spring.

He is survived by two sisters, Margaret Frohlich and Agnes Darraugh, and a brother, James, all of Brookly, N.Y.