William Buchanan
William or Bill Buchanan may refer to:
- William Buchanan (Manitoba politician), Irish-born Canadian Conservative politician
- William Buchanan (locomotive designer), designed trains for the New York Central
- William Buchanan (pastoralist), Australian pastoralist and gold prospector
- William Buchanan (footballer), Scottish amateur footballer
- William Buchanan (art dealer), British art dealer
- William Izett Buchanan, American expatriate basketball player
- William I. Buchanan, American diplomat
- William Ashbury Buchanan, journalist, publisher and politician based in Alberta
- William Murdoch Buchanan, Canadian politician and dentist
- Bill Buchanan (24), a fictional character in 24
- Bill Buchanan (computer scientist), Scottish computer scientist
- Bill Buchanan (songwriter), American songwriter
- Billy Buchanan, Scottish footballer with Carlisle United and Barrow