William Peacock may refer to: William Peacock (businessman) (1790–1874), Australian businessman and politician William Peacock (water polo) (1891–1948), British water polo player William D. Peacock (1933–1998), Native Canadian newspaper publisher William Peacock (biologist) (known as Jim Peacock, born 1937), Australian scientist Billy Peacock, boxer, see United States national amateur boxing flyweight champions