Duffin is a surname, and may refer to:
Adam Duffin (1841–1924), Irish unionist politician
Anne Duffin, historian
Graeme Duffin (born 1956), Scottish guitarist
Jackie Duffin (born 1950), Canadian medical historian and hematologist
Richard Duffin (1909–1996), American physicist
Shay Duffin (1931–2010), American actor
Terry Duffin (born 1982), Zimbabwean cricketer
