William Dwyer may refer to:
- William Dwyer (Irish politician) (1887–1951), Irish independent politician
- Bill Dwyer (mobster) (1883–1946), US Prohibition-era gangster
- William Lee Dwyer (1929–2002), U.S. federal judge
- Ubi Dwyer, Bill 'Ubi' Dwyer (1933-2001), Windsor Free Festival organiser
- Bil Dwyer (Born 1962), U.S. actor and comedian