William Whelan

William, Bill, or Billy Whelan may refer to:

• William Whelan (surgeon) (1808–1865), Chief of the US Bureau of Medicine and Surgery
• W. J. Whelan (union leader) (1887–1960), Irish union leader
• Billy Whelan (Scottish footballer) (1906–1982), Scottish footballer
• William Joseph Whelan (1924–2021), American biochemist, Fellow of the Royal Society
• Billy Whelan (1935–1958), Irish footballer
• Bill Whelan (born 1950), Irish musician