William Cowan
William Cowan may refer to:
- William Cowan (footballer), English footballer
- William Cowan (football manager), Scottish football manager in Spain
- William Cowan (fur trader), of the Hudson's Bay Company
- William Cowan (politician), reeve of North Gower Township, Ontario
- William Henry Cowan, Scottish politician
- W. [Maxwell Cowan], South African neuroscientist
- Mo Cowan, U.S. Senator from Massachusetts
- William Cowan (engineer)
- Bill Cowan, security expert
- Bill Cowan (tennis), Canadian tennis player
- Billy Cowan, retired baseball player
- Billy Cowan (footballer), Scottish footballer