William, Will, Bill, or Billy Davies may refer to:

Arts and literature

William Davies (actor) (1751–1809), English actor

William Davies (died 1819), English publisher with Cadell & Davies

William Edmund Davies (1819–1879), English bookmaker

W. H. Davies (William Henry Davies, 1871–1940), Welsh poet

William Davies (screenwriter) (fl. 1980s–2010s), British-born American screenwriter

Law and politics

William Davies (Georgia judge) (1775–1829), Georgia-based politician and lawyer

William Davies (Pembrokeshire MP) (1821–1895), British member of parliament (MP) for Pembrokeshire, 1880–1892

William Davies (New South Wales politician) (1824–1890)

William T. Davies (1831–1912), lieutenant governor of Pennsylvania, United States, 1887–1891

Sir William Howell Davies (politician) (1851–1932), British MP for Bristol South, 1906–1922

William Thomas Frederick Davies (1860–1947), South African surgeon, army officer and politician

William Rees-Davies (judge) (William Rees Morgan Davies, 1863–1939), British MP for Pembrokeshire, 1892–1898

Rupert Davies (politician) (William Rupert Davies, 1879–1967), Canadian author, newspaper publisher and senator

Billy Davies (politician) (1884–1956), Welsh-born Australian member of the New South Wales Legislative Assembly and the Australian Parliament

Sir William Arthian Davies (1901–1979), British lawyer and judge

William Gwynne Davies (1916–1999), trade unionist and politician in Saskatchewan, Canada

William H. Davies (1931–2017), justice of the Supreme Court of British Columbia

Military

William Davies (Virginia) (fl. 1770s), Continental Army officer in the American Revolutionary War

William Davies (fl. late 18th century), British bullet-mould maker, founder of arms manufacturer Webley & Scott

William W. Davies (USMC) (1900–1985), United States Marine Corps general

Religion

William Davies (priest) (died 1593), Welsh Roman Catholic priest and martyr

William W. Davies (1833–1906), leader of a schismatic Latter Day Saint group in Washington, United States

William David Davies (1897–1969), Welsh Presbyterian minister and theologian

Science and medicine

William Davies (palaeontologist) (1814–1891), British palaeontologist

William Broughton Davies (1831–1906), Sierra Leonean medical doctor

William Edward Davies (1917–1990), American geologist and caver

William Davies (psychologist) (born 1950), British psychologist

Sportspeople

Association football (soccer)

William Davies (footballer, born 1854) (1854–1916), Oswestry F.C. and Wales international footballer

William Davies (footballer, born 1873) (1873–1929), English footballer for Bolton Wanderers

William Davies (footballer, born 1882) (1882–1966), Wrexham F.C., Blackburn Rovers F.C. and Wales international footballer

Billy Davies (Welsh footballer) (1883–1960), Crystal Palace F.C., West Bromwich Albion F.C. and Wales international footballer

William Davies (footballer, born 1884) (1884–1954), footballer for Stoke

Willie Davies (footballer) (1900–1953), Swansea Town F.C., Cardiff City F.C., Notts County F.C.,Tottenham Hotspur F.C. and Wales international footballer

Taffy Davies (William Davies, 1910–1995), Welsh footballer with Watford

Dai Davies (footballer, born 1948) (William David Davies, 1948–2021), Welsh goalkeeper

Billy Davies (born 1964), Scottish footballer and manager

Will Davies (footballer), English footballer

Cricket

William Davies (English cricketer) (fl. 1844)

William Davies (cricketer, born 1825) (1825–1868), English cricketer and clergyman

Bill Davies (cricketer, born 1901) (1901–?), Welsh cricketer

Bill Davies (cricketer, born 1906) (1906–1971), Welsh cricketer

Billy Davies (cricketer, born 1936) (1936–2022), Welsh cricketer

William Davies (cricketer, born 1972), English cricketer

Rugby

William Davies (rugby) (1890–1967), Welsh rugby union and rugby league footballer of the 1910s and 1920s

Will Davies (rugby) (fl. 1910s), rugby league footballer for Great Britain, Wales and Halifax

Will Davies (rugby union) (1906–1975), Wales international rugby union player

Billy Davies (Welsh rugby) (William H. J. Davies, fl. 1930s), rugby union and rugby league footballer

Willie Davies (rugby) (1916–2002), Welsh dual-code rugby footballer

Bill Davies (rugby league) (fl. 1940s), rugby league footballer for Wales, and Huddersfield

Tony Davies (William Anthony Davies, 1939–2008), New Zealand rugby union footballer