William, Willie, Bill, or Billy Gray may refer to:

Arts and entertainment

• William S. Gray (film editor) (1896–1946), American film editor
• Billy Gray (comedian) (1904–1978), American comedian, comedy club owner, and actor
• Billy Gray (actor) (born 1938), American actor who portrayed teenager Bud Anderson on TV's Father Knows Best

Politics and law

• William Gray (Massachusetts politician) (1750–1825), American politician and merchant
• William Gray (Conservative politician) (1814–1895), British mill owner and Conservative Member of Parliament (MP) for Bolton 1857–1874
• William Gray (Canadian politician) (1862–1916), politician in Ontario, Canada
• William Gray (Lord Provost) (1928–2000), Lord Provost of Glasgow, 1972–1975
• William Gray (New Mexico politician) (born 1940), American state legislator in New Mexico
• William B. Gray (1942–1994), American attorney and politician
• William Bain Gray, British colonial administrator and civil servant
• William E. Gray, state legislator in Arkansas
• William H. Gray (Mississippi politician) (1841–1919), Baptist minister and state legislator in Mississippi
• William H. Gray (Oregon politician) (1810–1889), American pioneer of Oregon Country
• William H. Gray III (1941–2013), American Democrat from Pennsylvania
• Wilfred James "Bill" Gray, Australian government official, specialist in Aboriginal matters
• William Percival Gray (1912–1992), U.S. federal judge

Religion

• William Gray (priest) (1874–1960), Anglican clergyman
• William Crane Gray (1835–1919), American religious figure; first bishop of the Episcopal Church's Missionary Jurisdiction
  • SS William Crane Gray, a Liberty ship
• William Henry Gray (1825–1908), Scottish minister

Sports

American football

• Bill Gray (offensive lineman) (1922–2011), American offensive lineman for the Washington Redskins
• Bill Gray (Canadian football) (fl. 1960s), Canadian football running back
• Bill Gray (American football coach) (fl. 1990s–2000s), American football and tennis coach

Baseball

• Bill Gray (baseball) (1871–1932), American Major League Baseball player, 1890–1898
• Dolly Gray (baseball) (William Denton Gray, 1878–1956), American Major League Baseball pitcher for the Washington Senators, 1909–1911
• Willie Gray (fl. 1920–1937), American baseball player

Other sports

• William Gray (jockey) (fl. 1870), British Champion flat jockey
• William Gray (cricketer) (1864–1898), English cricketer
• Bill Gray (footballer) (1882–1916), Scottish footballer with Partick Thistle and Southampton in the 1900s
• Bill Gray (rugby union), (1932–1993), New Zealand rugby union player
• Billy Gray (footballer) (1927–2011), English footballer
• Billy Gray (horse trainer) (died 2016), horse trainer

Writing and academics

• William Forbes Gray (1874–1950), Scottish journalist and author
• William G. Gray (1913–1992), English occultist, author and mystic
• William M. Gray (1929–2016), American professor of atmospheric science
• William S. Gray (1885–1960), American academic, authority on the teaching of reading

Other fields

• William John Gray, 13th Lord Gray (1754–1807), Scottish nobleman and soldier
• W. H. Gray (William Henry Gray, 1808–1896), pioneer colonist of South Australia
• William Gray (inventor) (1850–1903), American inventor and entrepreneur, inventor of the payphone and the baseball chest protector
• William Gray (architect) (1851–1927), American architect
• William Gray (RAF officer) (1898–?), First World War flying ace
• one of the founders of William Gray & Company, a British shipbuilding company, established in 1863
• Bill Gray, co-founder (with his wife) of Bill Gray's, an American chain of fast-food restaurants based in New York State