William Fairfax (1691–1757) was the builder of the Belvoir estate and plantation.
William Fairfax may also refer to:
William Fairfax (died 1514), Justice of the Common Pleas William Fairfax (died 1597), MP for Boroughbridge and Yorkshire William Fairfax (soldier) (1609–1644) William George Fairfax (1739–1813), vice-admiral in the Royal Navy Sir William George Herbert Taylor Ramsay-Fairfax, 2nd Baronet (1831–1902), of the Fairfax Baronets
See also George William Fairfax, planter