William Lyon
William Lyon may refer to:
- William Lyon (film editor), American film editor
- William John Lyon, New Zealand politician
- William Lyon (bishop), English bishop
- William Lyon (priest), Anglican Archdeacon of Loughborough
- William Durie Lyon, Ontario businessman and politician
- William C. Lyon, American politician
- William P. Lyon, Wisconsin jurist and soldier
- William Radenhurst Richmond Lyon, first reeve of Richmond, Ontario
- Bill Lyon, Australian rules footballer
- Billy Lyon, American football player
- William Lyon (general), USAF general