William Gaines (disambiguation)

William Gaines (1922–1992) was an American publisher, notably of Mad magazine.

William Gaines may also refer to:
 * William E. Gaines (1844–1912), U.S. Representative from Virginia
 * William Gaines (professor) (1933–2016), American journalist and professor
 * William Gaines (American football) (born 1971), American footballer
 * Bill Gaines (basketball) (born 1946), retired basketball guard
 * William Gaines (minister and community leader), a freed slave who was a minister and community representative during the Reconstruction Era in Georgia