- Arthur C. Mellette Republican 1889-1893
- Charles H. Sheldon Republican 1893-1897
- Andrew E. Lee Populist 1897-1901
- Charles N. Herreid Republican 1901-1905
- Samuel H. Elrod Republican 1905-1907
- Coe I. Crawford Republican 1907-1909
- Robert S. Vessey Republican 1909-1913
- Frank M. Byrne Republican 1913-1917
- Peter Norbeck Republican 1917-1921
- W. H. McMaster Republican 1921-1925
- Carl Gunderson Republican 1925-1927
- W. J. Bulow Democratic 1927-1931
- Warren Green Republican 1931-1933
- Thomas Berry Democratic 1933-1937
- Leslie Jensen Republican 1937-1939
- Harlan J. Bushfield Republican 1939-1943
- M. Q. Sharpe Republican 1943-1947
- George T. Mickelson Republican 1947-1951
- Sigurd Anderson Republican 1951-1955
- Joe Foss Republican 1955-1959
- Ralph Herseth Democratic 1959-1961
- Archie Gubbrud Republican 1961-1965
- Nils Boe Republican 1965-1969
- Frank L. Farrar Republican 1969-1971
- Richard F. Kneip Democratic 1971-1978
- Harvey L. Wollman Democratic 1978-1979
- William J. Janklow Republican 1979-1987
- George S. Mickelson Republican 1987-1993
- Walter Dale Miller Republican 1993-1995
- William J. Janklow Republican 1995-2003
- Mike Rounds Republican 2003-