F. Ryan Duffy (1888–1979) was a U.S. Senator from Wisconsin from 1933 to 1939. Senator Duffy may also refer to:
Dan Duffy (born 1966), Illinois State Senate Francis Clyde Duffy (1890–1977), North Dakota State Senate Thomas A. Duffy (1906–1979), New York State Senate
See also Senator Duff (disambiguation) Senator Duffield (disambiguation)