William Mason
William, Willie, or Willy Mason may refer to:

Arts and entertainment
William Mason (poet) (1724–1797), English poet, editor and gardener
William Mason (architect) (1810–1897), New Zealand architect
William Mason (composer) (1829–1908), American composer and pianist
William W. Johnstone (a.k.a. William Mason, 1938–2004), American novelist
William Mason (director) (fl. 1990s–2010s), director of the Lyric Opera of Chicago
Willy Mason (born 1984), American singer-songwriter
William Mason (Downton Abbey), fictional character on the television series Downton Abbey

Business and industry
William Mason (locomotive builder) (1808–1883), American engineer and builder of locomotives
William Mason (gunsmith) (1837–1913), American engineer and inventor working for Remington, Colt, and Winchester
William H. Mason (masonite) (fl. 1920s), American inventor; first patented masonite

Law and politics

William Temple Thomson Mason (1782–1862), Virginia farmer, businessman and politician
William Mason (New York politician) (1786–1860), United States Representative from New York
William S. Mason (1832–1899), American politician; mayor of Portland, Oregon
William E. Mason (American politician) (1850–1921), U.S. Representative and Senator from Illinois
William Mason, 1st Baron Blackford (1862–1947), British politician and public servant
William E. Mason (Canadian politician) (1866–1951), Canadian politician; mayor of Regina, Saskatchewan
William E. Mason (East St. Louis mayor) (fl. 1970s), American politician; mayor of East Saint Louis, Illinois
William D. Mason (born 1959), American prosecutor from Cuyahoga County, Ohio

Military
William Mason (1757–1818), American planter and militiaman in the American Revolutionary War
William Mason (1760–1830), American Revolutionary War soldier, founder of city of Mason, Ohio
William Pinckney Mason (1843–1922), American lieutenant in the Confederate States Navy

Others
William Mason (stenographer) (fl. 1672–1709), English writing-master
William Mason (religious writer) (1719–1791), English Calvinist author and editor of the Gospel Magazine
William Shaw Mason (1774–1853), Irish statistician and bibliographer
William Mason (cricketer) (1811–1865), English cricketer
Willie Mason (born 1980), Australian rugby league footballer

Other uses
William Mason (locomotive), steam locomotive built for the Baltimore and Ohio Railroad

See also
Bill Mason (disambiguation)