William Mason
William, Willie, or Willy Mason may refer to:
Arts and entertainment
- William Mason (poet), English poet, editor and gardener
- William Mason (architect), New Zealand architect
- William Mason (composer), American composer and pianist
- William W. Johnstone, American novelist
- William Mason (director), director of the Lyric Opera of Chicago
- Willy Mason, American singer-songwriter
- William Mason (Downton Abbey), fictional character on the television series ''Downton Abbey''
Business and industry
- William Mason (locomotive builder), American engineer and builder of locomotives
- William Mason (gunsmith), American engineer and inventor working for Remington, Colt, and Winchester
- William H. Mason (masonite), American inventor; first patented masonite
Law and politics
- William Temple Thomson Mason, Virginia farmer, businessman and politician
- William Mason (New York politician), United States Representative from New York
- William S. Mason, American politician; mayor of Portland, Oregon
- William E. Mason (American politician), U.S. Representative and Senator from Illinois
- William Mason, 1st Baron Blackford, British politician and public servant
- William E. Mason (Canadian politician), Canadian politician; mayor of Regina, Saskatchewan
- William E. Mason (East St. Louis mayor), American politician; mayor of East Saint Louis, Illinois
- William D. Mason, American prosecutor from Cuyahoga County, Ohio
Military
- William Mason (1757–1818), American planter and militiaman in the American Revolutionary War
- William Mason, American Revolutionary War soldier, founder of city of Mason, Ohio
- William Pinckney Mason, American lieutenant in the Confederate States Navy
Others
- William Mason (stenographer), English writing-master
- William Mason (religious writer), English Calvinist author and editor of the Gospel Magazine
- William Shaw Mason, Irish statistician and bibliographer
- William Mason (cricketer), English cricketer
- Willie Mason, Australian rugby league footballer