William Matthew Ketchum (September 2, 1921 – June 24, 1978) was a U.S. Representative from California.Ketchum was born on September 2, 1921 in Los Angeles, California. He attended schools in Los Angeles County and military school in North Hollywood, California.He attended Colorado School of Mines from 1939 to 1940, and the University of Southern California from 1940 to 1942. He entered the United States Army in 1942 and served in the Pacific before discharge in 1946.