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 Wilkinson Addison (1905–1992), English historian and jurist