This is a complete list of United States senators during the 115th United States Congress listed by seniority from January 3, 2017, to January 3, 2019. It is a historical listing and will contain people who have not served the entire two-year Congress on account of resignations, deaths, or expulsions.

In this Congress, Bill Cassidy is the most junior senior senator. Jeff Sessions was the most senior junior senator at the start of this Congress, but resigned on February 8, 2017, to become United States Attorney General. Maria Cantwell has remained the most senior junior senator since.

Order of service is based on the commencement of the senator's first term. Behind this is former service as a senator (only giving the senator seniority within their new incoming class), service as vice president, a House member, a cabinet secretary, or a governor of a state. The final factor is the population of the senator's state.A Chronological List of United States Senators 1789-Present, via www.senate.gov1971 U.S Census Report Contains 1970 census results.1981 U.S Census Report Contains 1980 census results.1991 U.S Census Report Contains 1990 census results.

Terms of service

ClassTerms of service of senators that expired in yearsClass 1Terms of service of senators that expired in 2019 (Arizona, California, Connecticut, Delaware, Florida, Hawaii, Indiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Jersey, New Mexico, New York, North Dakota, Ohio, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, and Wyoming.)Terms of service of senators that expired in 2019.Class 2Terms of service of senators that expired in 2021 (Alabama, Alaska, Arkansas, Colorado, Delaware, Georgia, Iowa, Idaho, Illinois, Kansas, Kentucky, Louisiana, Massachusetts, Maine, Michigan, Minnesota, Mississippi, Montana, North Carolina, Nebraska, New Hampshire, New Jersey, New Mexico, Oklahoma, Oregon, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Virginia, West Virginia, and Wyoming.)Terms of service of senators that expired in 2021.Class 3Terms of service of senators that expired in 2023 (Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Iowa, Indiana, Kansas, Kentucky, Louisiana, Massachusetts, Maine, Michigan, Minnesota, Mississippi, North Carolina, North Dakota, New Hampshire, New Mexico, Nevada, New York, Oklahoma, Oregon, South Carolina, South Dakota, Tennessee, Utah, Washington and Wisconsin.)Terms of service of senators that expired in 2023.

U.S. Senate seniority list Rank Historicalrank Senator Party State Seniority date Other factors 1 1692 Democratic Vermont January 3, 1975   2 1708 Republican Utah January 3, 1977 3 1719 Republican Mississippi December 27, 1978 4 1743 Republican Iowa January 3, 1981 5 1766 Republican Kentucky January 3, 1985 6 1775 Republican Alabama January 3, 1987 Former member of the U.S. House of Representatives (8 years) 7 1777 Republican Arizona Former member of the U.S. House of Representatives (4 years) 8 1801 Democratic California November 10, 1992   9 1812 Democratic Washington January 3, 1993 10 1816 Republican Oklahoma November 17, 1994 11 1827 Democratic Oregon February 6, 1996 12 1830 Republican Kansas January 3, 1997 Former member of the U.S. House of Representatives (16 years) 13 1831 Democratic Illinois Former member of the U.S. House of Representatives (14 years) 14 1835 Democratic Rhode Island Former member of the U.S. House of Representatives (6 years) 15 1839 Republican Alabama Alabama 22nd in population (1990) 16 1842 Republican Maine Maine 38th in population (1990) 17 1843 Republican Wyoming Wyoming 50th in population (1990) 18 1844 Democratic New York January 3, 1999 Former member of the U.S. House of Representatives (18 years) 19 1846 Republican Idaho Former member of the U.S. House of Representatives (6 years) 20 1854 Democratic Florida January 3, 2001 Former member of the U.S. House of Representatives (12 years) 21 1855 Democratic Delaware Former member of the U.S. House of Representatives (10 years) 22 1856 Democratic Michigan Former member of the U.S. House of Representatives (4 years) 23 1859 Democratic Washington Former member of the U.S. House of Representatives (2 years) 24 1873 Republican Texas December 1, 2002   25 1867 Republican Alaska December 20, 2002 26 1869 Republican South Carolina January 3, 2003 Former member of the U.S. House of Representatives 27 1871 Republican Tennessee   28 1876 Republican North Carolina January 3, 2005 Former member of the U.S. House of Representatives (10 years) 29 1879 Republican South Dakota Former member of the U.S. House of Representatives (6 years) 30 1880 Republican Georgia Former member of the U.S. House of Representatives (5 years, 10 months) 31 1885 Democratic New Jersey January 18, 2006   32 1886 Democratic Maryland January 3, 2007 Former member of the U.S. House of Representatives (20 years) 33 1887 Independent Vermont Former member of the U.S. House of Representatives (16 years). 34 1888 Democratic Ohio Former member of the U.S. House of Representatives (14 years) 35 1889 Democratic Pennsylvania Pennsylvania 6th in population (2000) 36 1891 Republican Tennessee Tennessee 16th in population (2000) 37 1892 Democratic Missouri Missouri 17th in population (2000) 38 1893 Democratic Minnesota Minnesota 21st in population (2000) 39 1894 Democratic Rhode Island Rhode Island 43rd in population (2000) 40 1895 Democratic Montana Montana 44th in population (2000) 41 1896 Republican Wyoming June 25, 2007   42 1897 Republican Mississippi December 31, 2007 43 1899 Democratic New Mexico January 3, 2009 Former member of the U.S. House of Representatives 44 1901 Democratic New Hampshire Former governor (6 years) 45 1902 Democratic Virginia Former governor (4 years) 46 1903 Republican Idaho Former governor (7 months) 47 1905 Democratic Oregon   48 1909 Democratic Colorado January 21, 2009 49 1910 Democratic New York January 26, 2009 50 1911 Democratic Minnesota July 7, 2009 51 1916 Democratic West Virginia November 15, 2010 Former governor 52 1917 Democratic Delaware   53 1919 Republican Missouri January 3, 2011 Former member of the U.S. House of Representatives (14 years); Missouri 17th in population (2000) 54 1920 Republican Kansas Former member of the U.S. House of Representatives (14 years); Kansas 32nd in population (2000) 55 1921 Republican Ohio Former member of the U.S. House of Representatives (12 years) 56 1922 Republican Arkansas Former member of the U.S. House of Representatives (9 years) 57 1923 Republican Pennsylvania Former member of the U.S. House of Representatives (6 years) 58 1924 Republican North Dakota Former governor 59 1925 Republican Florida Florida 4th in population (2000) 60 1926 Republican Wisconsin Wisconsin 18th in population (2000) 61 1927 Republican Kentucky Kentucky 25th in population (2000) 62 1928 Democratic Connecticut Connecticut 29th in population (2000) 63 1929 Republican Utah Utah 34th in population (2000) 64 1931 Republican Nevada May 9, 2011   65 1932 Democratic Hawaii December 27, 2012 66 1933 Republican South Carolina January 2, 2013 67 1934 Democratic Wisconsin January 3, 2013 Former member of the U.S. House of Representatives (14 years) 68 1935 Republican Arizona Former member of the U.S. House of Representatives (12 years) 69 1936 Democratic Indiana Former member of the U.S. House of Representatives (6 years); Indiana 16th in population (2010) 70 1937 Democratic Connecticut Former member of the U.S. House of Representatives (6 years); Connecticut 29th in population (2010) 71 1938 Democratic Hawaii Former member of the U.S. House of Representatives (6 years); Hawaii 42nd in population (2010) 72 1939 Democratic New Mexico Former member of the U.S. House of Representatives (4 years) 73 1940 Independent Maine Former governor (8 years) 74 1941 Democratic Virginia Former governor (4 years) 75 1942 Republican Texas Texas 2nd in population (2010) 76 1943 Democratic Massachusetts Massachusetts 15th in population (2010) 77 1944 Republican Nebraska Nebraska 38th in population (2010) 78 1945 Democratic North Dakota North Dakota 48th in population (2010) 79 1948 Democratic Massachusetts July 16, 2013   80 1949 Democratic New Jersey October 31, 2013 81 1951 Republican West Virginia January 3, 2015 Former member of the U.S. House of Representatives (14 years) 82 1952 Democratic Michigan Former member of the U.S. House of Representatives (6 years); Michigan 9th in population (2010) 83 1953 Republican Louisiana Former member of the U.S. House of Representatives (6 years); Louisiana 25th in population (2010) 84 1954 Republican Colorado Former member of the U.S. House of Representatives (4 years); Colorado 22nd in population (2010) 85 1955 Republican Oklahoma Former member of the U.S. House of Representatives (4 years); Oklahoma 28th in population (2010) 86 1956 Republican Arkansas Former member of the U.S. House of Representatives (2 years); Arkansas 32nd in population (2010) 87 1957 Republican Montana Former member of the U.S. House of Representatives (2 years); Montana 44th in population (2010) 88 1958 Republican South Dakota Former governor 89 1959 Republican Georgia Georgia 8th in population (2010) 90 1960 Republican North Carolina North Carolina 10th in population (2010) 91 1961 Republican Iowa Iowa 30th in population (2010) 92 1962 Republican Nebraska Nebraska 37th in population (2010) 93 1963 Republican Alaska Alaska 47th in population (2010) 94 1964 Democratic Maryland January 3, 2017 Former member of the U.S. House of Representatives (14 years) 95 1965 Republican Indiana Former member of the U.S. House of Representatives (6 years) 96 1966 Democratic Illinois Former member of the U.S. House of Representatives (4 years) 97 1967 Democratic New Hampshire Former governor 98 1968 Democratic California California 1st in population (2010) 99 1969 Republican Louisiana Louisiana 25th in population (2010) 100 1970 Democratic Nevada Nevada 35th in population (2010) 1971 Republican Alabama February 9, 2017   1972 Democratic Minnesota January 3, 2018 Minnesota 21st in population (2010) 1973 Democratic Alabama Alabama 23rd in population (2010) 1974 Cindy Hyde-Smith Republican Mississippi April 2, 2018   1820 Jon Kyl Republican Arizona September 4, 2018

The most senior senators by class were Orrin Hatch (R-Utah) from Class 1, Thad Cochran (R-Mississippi) from Class 2, and Patrick Leahy (D-Vermont) from Class 3. Cochran resigned on April 1, 2018, with Mitch McConnell (R-Kentucky) became the most senior senator from his class.

See also 115th United States Congress List of United States representatives in the 115th Congress

Notes

References

External links