William Capell

William Capell may refer to:


 * William Capel (died 1515), Lord Mayor of London
 * William Capell, 3rd Earl of Essex (1697–1743), 3rd Earl of Essex
 * William Capell, 4th Earl of Essex (1732–1799), 4th Earl of Essex
 * William Capel (sportsman) (1775–1854), sportsman and priest
 * William Jennings Capell (born 1952), American heir presumptive to the earldom of Essex