William Addison may refer to:

• William Addison (physician) (1803–1881), British physician
• William Addison (VC) (1883–1962), holder of the Victoria Cross
• William Addison, 4th Viscount Addison (born 1945), British Conservative peer
• William Addison (chess player) (1933–2008), American chess master
• William Fountaine Addison (1817-1893), clergyman, Canon of Gibraltar
• William Grylls Addison (1853-1904), English landscape painter
• William Wilkinson Addison (1905–1992), English historian and jurist