William, Will, Bill or Billy Dean is the name of the following people:
Arts and entertainment
Bill Dean (1921–2000), British actor
Billy Dean (born 1962), American country music singer
Sports
William Dean (Hampshire cricketer) (c. 1882–?), Australian cricketer
William Henry Dean (1887–1949), English water polo player
Dixie Dean (1907–1980), English footballer
William Dean (Somerset cricketer) (1926–1994), English cricketer
Bill Dean (baseball) (fl. 1940), American baseball player
Will Dean (rower) (born 1987), Canadian rower
Will Dean (footballer) (born 2000), English footballer
Other fields
William Dean (priest) (died 1588), English priest and martyr
William Dean (engineer) (1840–1905), British railway engineer
William Reginald Dean (1896–1973), British applied mathematician
William F. Dean (1899–1981), United States Army general
William D. Dean (born 1940), American politician and television producer
Will Dean (entrepreneur) (born 1980), English business founder
Bill Dean (politician), American legislator from Ohio