William Cecil may refer to:
Lord William Cecil (courtier) (1854–1943), British royal courtier Lord William Cecil (bishop) (1863–1936), Bishop of Exeter, 1916–1936 William Cecil, 1st Baron Burghley (1520–1598), English politician and advisor to Elizabeth I William Cecil, 2nd Earl of Exeter (1566–1640), Knight of the Garter William Cecil, 2nd Earl of Salisbury (1591–1668), Knight of the Garter William Cecil, 3rd Marquess of Exeter (1825–1895), member of the Privy Council of the United Kingdom William Cecil, 5th Marquess of Exeter (1876–1956), recipient of the Territorial Decoration William Cecil, 7th Marquess of Exeter (1909–1988), son of William Cecil, 5th Marquess of Exeter William Cecil, 17th Baron de Ros (1590–1618), Baron in the Peerage of England
William Amherst Vanderbilt Cecil (1928–2017), operator of the Biltmore Estate William Cecil Ross (1911–1998), politician in Manitoba, Canada William Cecil Slingsby (1849–1929), English mountain climber and alpine explorer