William Neilson may refer to:
William Neilson (Lord Provost), Lord Provost of Edinburgh 1717 to 1719 William Neilson (businessman) (1844–1915), Canadian businessman William Neilson (Manitoba politician) (1854–1903), physician and politician in Manitoba, Canada Willie Neilson (1873–1960), Scottish rugby player William Allan Neilson (1869–1946), Scottish-American educator William Neilson (cricketer) (1848–1880), English-born New Zealand cricketer William George Neilson (1862–1899), Canadian politician in the Legislative Assembly of British Columbia Bill Neilson (1925–1989), Premier of Tasmania
See also William Nelson (disambiguation)