William Mann
William Mann may refer to:
- William Mann , English astronomer active in the Cape Colony
- William Mann, English politician in the House of Commons, 1621–1625
- William Mann , original settler of Providence, Rhode Island
- William Abram Mann, general officer in the United States Army
- William d'Alton Mann, American Civil War soldier and newspaper and magazine publisher
- William C. Mann "Bill", computational linguist
- William Mann , senior Royal Air Force officer and flying ace
- Billy Mann, record producer/singer/songwriter
- William Hodges Mann, American politician
- William Mann , English cricketer
- William J. Mann, American author and gay historian
- William Mann , Australian politician
- William Julius Mann, American Lutheran theologian and author
- William M. Mann, entomologist and director of the National Zoo, Washington, D.C., 1925–1956
- William Mann , American mathematician
- William Mann , British music critic for The Times
- William Mann, English international rugby union player
- Billy Mann, Australian international rugby union player