William Cadogan may refer to:
William Cadogan (politician) (1601–1661) William Cadogan, 1st Earl Cadogan (1675–1726) William Cadogan (childcare writer) (1711–1797), British physician and childcare writer William Bromley Cadogan (1751–1797), English priest William G. S. Cadogan (1879–1914), British Army officer William Cadogan, 7th Earl Cadogan (1914–1997)