Total tenure rank Uninterrupted tenure rank Name State represented Dates of service Total tenure Uninterrupted tenure Robert Byrd West Virginia January 3, 1959 -- June 28, 2010 51 years, 176 days 51 years, 176 days Daniel Inouye Hawaii January 3, 1963 -- December 17, 2012 49 years, 349 days 49 years, 349 days Strom Thurmond (I) South Carolina December 24, 1954 -- April 7, 1956 November 7, 1956 -- January 3, 2003 47 years, 159 days 46 years, 57 days Ted Kennedy Massachusetts November 7, 1962 -- August 25, 2009 46 years, 292 days 46 years, 292 days 5 5 Patrick Leahy Vermont Since January 3, 1975 7004158510000000000 ♠ 43 years, 145 days 7004158510000000000 ♠ 43 years, 145 days 6 6 Carl Hayden Arizona March 4, 1927 -- January 3, 1969 41 years, 305 days 41 years, 305 days 7 7 Orrin Hatch Utah Since January 3, 1977 7004151200000000000 ♠ 41 years, 145 days 7004151200000000000 ♠ 41 years, 145 days 8 8 John C. Stennis Mississippi November 7, 1947 -- January 3, 1989 41 years, 59 days 41 years, 59 days 9 9 Ted Stevens Alaska December 24, 1968 -- January 3, 2009 40 years, 10 days 40 years, 10 days 10 10 Thad Cochran Mississippi December 27, 1978 -- April 1, 2018 39 years, 94 days 39 years, 94 days 11 11 Ernest Hollings South Carolina November 8, 1966 -- January 3, 2005 38 years, 55 days 38 years, 55 days 12 12 Richard Russell Jr. Georgia January 12, 1933 -- January 21, 1971 38 years, 9 days 38 years, 9 days 13 13 Russell B. Long Louisiana December 31, 1948 -- January 3, 1987 38 years, 3 days 38 years, 3 days 14 14 Chuck Grassley Iowa Since January 3, 1981 7004136590000000000 ♠ 37 years, 145 days 7004136590000000000 ♠ 37 years, 145 days 15 999 Francis E. Warren (I) Wyoming November 18, 1890 -- March 4, 1893 March 4, 1895 -- November 24, 1929 37 years, 6 days n / a 16 999 James Eastland (I) Mississippi June 30 -- September 28, 1941 January 3, 1943 -- December 27, 1978 36 years, 83 days n / a 17 15 Warren Magnuson Washington December 14, 1944 -- January 3, 1981 36 years, 20 days 36 years, 20 days 18 16 Joe Biden Delaware January 3, 1973 -- January 15, 2009 36 years, 12 days 36 years, 12 days 19 17 Claiborne Pell Rhode Island January 3, 1961 -- January 3, 1997 36 years, 0 days 36 years, 0 days 20 18 Pete Domenici New Mexico January 3, 1973 -- January 3, 2009 36 years, 0 days 36 years, 0 days 21 19 Richard Lugar Indiana January 3, 1977 -- January 3, 2013 36 years, 0 days 36 years, 0 days 22 20 Carl Levin Michigan January 3, 1979 -- January 3, 2015 36 years, 0 days 36 years, 0 days
who is currently the longest serving member of the senate
Patrick Leahy