William, Bill, Billy, or Willie Riley may refer to:
Sports William Riley (Nottinghamshire cricketer) (1888–1917) William Riley (Leicestershire cricketer) (1892–1955) Bill Riley (ice hockey, born 1921) (1921–2000), American ice hockey player Bill Riley (ice hockey, born 1950) (1950–2026), Canadian ice hockey player Bill Riley Jr., American ice hockey player and coach Billy Riley (1889–1977), English professional wrestler, coach, promoter, and referee Billy Riley (baseball) (1855–1887), outfielder in Major League Baseball
Arts and entertainment Willie Riley (1866–1961), British author William K. Riley, one of the pen names of British author John Creasey (1908–1973) Bill Riley Sr. (1920–2006), American entertainer Billy Lee Riley (1933–2009), American musician
Other William Riley (architect) (1852–1937), British architect William J. Riley (1947–2023), United States federal judge William F. Riley (judge) (1884–1956), United States federal judge William F. Riley (engineer) (1925–2000), American engineer and academic William Harrison Riley (1835–1907), British socialist William Bell Riley (1861–1947), American religious leader William Riley (criminal), a.k.a. "Mush" Riley, American saloon keeper and underworld figure William E. Riley (1897–1970), American general
See also William Reilly (disambiguation) Riley (surname) William O'Reilly (disambiguation)