William Gage may refer to:
People William Gage (15th-century landowner) (1447–1497) Sir William Gage, 2nd Baronet (c. 1650–1727)
Sir William Gage, 7th Baronet (1695–1744), MP for Seaford from 1727 until his death William Gage, 2nd Viscount Gage (1718–1791), equerry to the Prince of Wales and Member of Parliament William Hall Gage (1777–1864), Second Sea Lord and Admiral of the Fleet in the British Navy William James Gage (1849–1921), Canadian publisher and philanthropist William J. Gage (1891–1965), American architect, designed Beverly Hills City Hall Sir William Gage (judge) (1938–2023), UK Lord Justice of Appeal
Other Sir William Gage Middle School, in Brampton, Ontario, Canada