John Duffy

• History of medicine in the United States
• Jack Duffy
• Jack Duffy (actor)
• John A. Duffy
• John Duffy (Gaelic footballer)
• John Duffy (composer)
• John Duffy (economist)
• John Duffy (footballer, born 1886)
• John Duffy (footballer, born 1922)
• John Duffy (footballer, born 1929)
• John Duffy (footballer, born 1943)
• John Duffy (medical historian)
• John Duffy (mobster)
• John Duffy (rugby league)
• John Duffy (soccer)
• John Duffy (writer)
• John Duffy and David Mulcahy
• John F. Duffy
• John Gavan Duffy
• John J. Duffy Jr.