William McCoy or MacCoy may refer to:
W. F. McCoy (1886–1976), Speaker of the Northern Ireland House of Commons William McCoy (rum runner) (1877–1948), American rum-runner during Prohibition William McCoy (congressman) (died 1864), American politician and member of Congress William McCoy (mutineer) (c. 1763–1798), Scottish mutineer on HMS Bounty William McCoy (Oregon politician) (1921–1996), American politician and member of the Oregon Legislative Assembly William D. McCoy (1853–1893), American diplomat William F. MacCoy (1840–1914), lawyer and politician in Nova Scotia, Canada William J. McCoy (composer) (1848–1926), American composer William J. McCoy (Mississippi politician) (1942–2019), American politician and Speaker of the Mississippi House of Representatives William John McCoy (1834–1897), American politician and member of the Wisconsin State Assembly Willie McCoy (rapper) (died 2019), rapper Bill McCoy (cricketer) (1906–1980), New Zealand cricketer