| Class 2Class 2 U.S. senators belong to the electoral cycle that has recently been contested in 2002, 2008, 2014, and 2020. The next election will be in 2026. |
C |
Class 3Class 3 U.S. senators belong to the electoral cycle that has recently been contested in 2004, 2010, 2016, and 2022. The next election will be in 2028. |
| # |
Senator |
Party |
Dates in office |
Electoral history |
T |
T |
Electoral history |
Dates in office |
Party |
Senator |
# |
| 1 |
 Jesse B. Thomas |
Democratic- Republican |
Dec 3, 1818 – Mar 3, 1829 |
Elected in 1818. |
1 |
15th |
1 |
Elected in 1818. |
Dec 3, 1818 – Mar 3, 1824 |
Democratic- Republican |
 Ninian Edwards |
1 |
| 16th |
2 |
Re-elected in 1819.Resigned. |
| 17th |
| Re-elected in 1823.Retired. |
2 |
18th |
| |
Mar 4, 1824 – Nov 24, 1824 |
Vacant |
| Elected to finish Edwards's term.Retired. |
Nov 24, 1824 – Mar 3, 1825 |
Democratic- Republican |
 John McLean |
2 |
National Republican |
19th |
3 |
Elected in 1825. |
Mar 4, 1825 – Dec 12, 1835 |
Jacksonian |
 Elias Kane |
3 |
| 20th |
| 2 |
 John McLean |
Jacksonian |
Mar 4, 1829 – Oct 14, 1830 |
Elected in 1829.Died. |
3 |
21st |
| Vacant |
Oct 14, 1830 – Nov 12, 1830 |
|
| 3 |
 David J. Baker |
Jacksonian |
Nov 12, 1830 – Dec 11, 1830 |
Appointed to continue McLean's term.Retired. |
| 4 |
 John M. Robinson |
Jacksonian |
Dec 11, 1830 – Mar 3, 1841 |
Elected to finish McLean's term. |
| 22nd |
4 |
Re-elected in 1831.Died. |
| 23rd |
| Re-elected in 1835.Retired. |
4 |
24th |
| |
Dec 12, 1835 – Dec 30, 1835 |
Vacant |
| Appointed to finish Kane's term.Lost election to full term. |
Dec 30, 1835 – Mar 3, 1837 |
Jacksonian |
 William Lee D. Ewing |
4 |
| Democratic |
25th |
5 |
Elected in 1837.Retired. |
Mar 4, 1837 – Mar 3, 1843 |
Democratic |
 Richard M. Young |
5 |
| 26th |
| 5 |
 Samuel McRoberts |
Democratic |
Mar 4, 1841 – Mar 27, 1843 |
Elected in 1841.Died. |
5 |
27th |
| 28th |
6 |
Elected in 1843.Lost renomination. |
Mar 4, 1843 – Mar 3, 1849 |
Democratic |
 Sidney Breese |
6 |
| Vacant |
Mar 27, 1843 – Aug 16, 1843 |
|
| 6 |
 James Semple |
Democratic |
Aug 16, 1843 – Mar 3, 1847 |
Appointed to continue McRoberts's term.Elected in 1844 to finish McRoberts's term.Retired. |
| 29th |
| 7 |
 Stephen A. Douglas |
Democratic |
Mar 4, 1847 – Jun 3, 1861 |
Elected in 1846. |
6 |
30th |
| 31st |
7 |
Elected in 1849.[2]Election voided.[a] |
Mar 4, 1849 – Mar 15, 1849 |
Democratic |
 James Shields |
7 |
| |
Mar 15, 1849 – Oct 27, 1849 |
Vacant |
| Elected to finish his own term.Lost re-election. |
Oct 27, 1849 – Mar 3, 1855 |
Democratic |
 James Shields |
| 32nd |
| Re-elected in 1852. |
7 |
33rd |
| 34th |
8 |
Elected in 1855. |
Mar 4, 1855 – Mar 3, 1873 |
Democratic |
 Lyman Trumbull |
8 |
| 35th |
Republican |
| Re-elected in 1859.Died. |
8 |
36th |
| 37th |
9 |
Re-elected in 1861. |
| Vacant |
Jun 3, 1861 – Jun 26, 1861 |
|
| 8 |
 Orville Browning |
Republican |
Jun 26, 1861 – Jan 12, 1863 |
Appointed to continue Douglas's term.Retired. |
| 9 |
 William A. Richardson |
Democratic |
Jan 12, 1863 – Mar 3, 1865 |
Elected to finish Douglas's term.Retired. |
| 38th |
| 10 |
 Richard Yates |
Republican |
Mar 4, 1865 – Mar 3, 1871 |
Elected in 1864 or 1865.Retired. |
9 |
39th |
| 40th |
10 |
Re-elected in 1867.[data missing] |
| 41st |
| 11 |
 John A. Logan |
Republican |
Mar 4, 1871 – Mar 3, 1877 |
Elected in 1870 or 1871.Lost re-election. |
10 |
42nd |
Liberal Republican |
| 43rd |
11 |
Elected in 1873.Retired. |
Mar 4, 1873 – Mar 3, 1879 |
Republican |
 Richard J. Oglesby |
9 |
| 44th |
| 12 |
 David Davis |
Independent |
Mar 4, 1877 – Mar 3, 1883 |
Elected in 1877.Retired. |
11 |
45th |
| 46th |
12 |
Elected in 1879. |
Mar 4, 1879 – Mar 3, 1885 |
Republican |
 John A. Logan |
10 |
| 47th |
| 13 |
 Shelby M. Cullom |
Republican |
Mar 4, 1883 – Mar 3, 1913 |
Elected in 1882. |
12 |
48th |
| 49th |
13 |
Legislature failed to elect. |
Mar 4, 1885 – May 18, 1885 |
Vacant |
| Re-elected late in 1885.Died. |
May 19, 1885 – Dec 26, 1886 |
Republican |
 John A. Logan |
| |
Dec 26, 1886 – Jan 19, 1887 |
Vacant |
| Elected to finish Logan's term.Retired. |
Jan 19, 1887 – Mar 3, 1891 |
Republican |
 Charles Farwell |
11 |
| 50th |
| Re-elected in 1888. |
13 |
51st |
| 52nd |
14 |
Elected in 1890.Retired. |
Mar 4, 1891 – Mar 3, 1897 |
Democratic |
 John Palmer |
12 |
| 53rd |
| Re-elected in 1894. |
14 |
54th |
| 55th |
15 |
Elected in 1897.[3]Retired. |
Mar 4, 1897 – Mar 3, 1903 |
Republican |
 William Mason |
13 |
| 56th |
| Re-elected in 1901. |
15 |
57th |
| 58th |
16 |
Elected in 1903.Lost re-election. |
Mar 4, 1903 – Mar 3, 1909 |
Republican |
 Albert Hopkins |
14 |
| 59th |
| Re-elected in 1907.[4]Lost renomination. |
16 |
60th |
| 61st |
17 |
|
Mar 4, 1909 – Jun 18, 1909 |
Vacant |
| Elected in 1909, but ineligible until resignation from U.S. House.Election voided. |
Jun 18, 1909 – Jul 13, 1912 |
Republican |
 William Lorimer |
15 |
| 62nd |
| |
Jul 13, 1912 – Mar 26, 1913 |
Vacant |
| Vacant |
Mar 4, 1913 – Mar 26, 1913 |
Legislature elected late. |
17 |
63rd |
| 14 |
 J. Hamilton Lewis |
Democratic |
Mar 26, 1913 – Mar 3, 1919 |
Elected late in 1913.Lost re-election. |
Elected in 1913 to finish Lorimer's term. |
Mar 26, 1913 – Mar 3, 1921 |
Republican |
 Lawrence Y. Sherman |
16 |
| 64th |
18 |
Re-elected in 1914.Retired. |
| 65th |
| 15 |
 Medill McCormick |
Republican |
Mar 4, 1919 – Feb 25, 1925 |
Elected in 1918.Lost renomination and died just before the end of the term. |
18 |
66th |
| 67th |
19 |
Elected in 1920.Lost renomination and died just before the end of the term. |
Mar 4, 1921 – Dec 7, 1926 |
Republican |
 William B. McKinley |
17 |
| 68th |
| 16 |
 Charles S. Deneen |
Republican |
Feb 26, 1925 – Mar 3, 1931 |
Appointed to finish McCormick's term, having already been elected to the next term. |
| Elected in 1924.Lost renomination. |
19 |
69th |
| Appointed to continue McKinley's term.Not seated/resigned.[b] |
Dec 7, 1926 |
Republican |
 Frank L. Smith |
18 |
| |
Dec 7, 1926 – Dec 3, 1928 |
Vacant |
| 70th |
20 |
| Elected to finish the term.Lost re-election. |
Dec 3, 1928 – Mar 3, 1933 |
Republican |
 Otis F. Glenn |
19 |
| 71st |
| 17 |
 J. Hamilton Lewis |
Democratic |
Mar 4, 1931 – Apr 9, 1939 |
Elected in 1930. |
20 |
72nd |
| 73rd |
21 |
Elected in 1932.Retired. |
Mar 4, 1933 – Jan 3, 1939 |
Democratic |
 William H. Dieterich |
20 |
| 74th |
| Re-elected in 1936.Died. |
21 |
75th |
| 76th |
22 |
Elected in 1938. |
Jan 3, 1939 – Jan 3, 1951 |
Democratic |
 Scott W. Lucas |
21 |
| Vacant |
Apr 9, 1939 – Apr 14, 1939 |
|
| 18 |
 James M. Slattery |
Democratic |
Apr 14, 1939 – Nov 21, 1940 |
Appointed to continue Lewis's term.Lost election to finish Lewis's term. |
| 19 |
 C. Wayland Brooks |
Republican |
Nov 22, 1940 – Jan 3, 1949 |
Elected to finish Lewis's term. |
| 77th |
| Re-elected in 1942.Lost re-election. |
22 |
78th |
| 79th |
23 |
Re-elected in 1944.Lost re-election. |
| 80th |
| 20 |
 Paul Douglas |
Democratic |
Jan 3, 1949 – Jan 3, 1967 |
Elected in 1948. |
23 |
81st |
| 82nd |
24 |
Elected in 1950. |
Jan 3, 1951 – Sep 7, 1969 |
Republican |
 Everett Dirksen |
22 |
| 83rd |
| Re-elected in 1954. |
24 |
84th |
| 85th |
25 |
Re-elected in 1956. |
| 86th |
| Re-elected in 1960.Lost re-election. |
25 |
87th |
| 88th |
26 |
Re-elected in 1962. |
| 89th |
| 21 |
 Charles H. Percy |
Republican |
Jan 3, 1967 – Jan 3, 1985 |
Elected in 1966. |
26 |
90th |
| 91st |
27 |
Re-elected in 1968.Died. |
| |
Sep 7, 1969 – Sep 17, 1969 |
Vacant |
| Appointed to continue Dirksen's term.Lost election to finish Dirksen's term. |
Sep 17, 1969 – Nov 3, 1970 |
Republican |
 Ralph T. Smith |
23 |
| |
Nov 3, 1970 – Nov 17, 1970 |
Vacant |
| Elected to finish Dirksen's term. |
Nov 17, 1970 – Jan 3, 1981 |
Democratic |
 Adlai Stevenson III |
24 |
| 92nd |
| Re-elected in 1972. |
27 |
93rd |
| 94th |
28 |
Re-elected in 1974.Retired. |
| 95th |
| Re-elected in 1978.Lost re-election. |
28 |
96th |
| 97th |
29 |
Elected in 1980. |
Jan 3, 1981 – Jan 3, 1993 |
Democratic |
 Alan J. Dixon |
25 |
| 98th |
| 22 |
 Paul Simon |
Democratic |
Jan 3, 1985 – Jan 3, 1997 |
Elected in 1984. |
29 |
99th |
| 100th |
30 |
Re-elected in 1986.Lost renomination. |
| 101st |
| Re-elected in 1990.Retired. |
30 |
102nd |
| 103rd |
31 |
Elected in 1992.Lost re-election. |
Jan 3, 1993 – Jan 3, 1999 |
Democratic |
 Carol Moseley Braun |
26 |
| 104th |
| 23 |
 Dick Durbin |
Democratic |
Jan 3, 1997 – present |
Elected in 1996. |
31 |
105th |
| 106th |
32 |
Elected in 1998.Retired. |
Jan 3, 1999 – Jan 3, 2005 |
Republican |
 Peter Fitzgerald |
27 |
| 107th |
| Re-elected in 2002. |
32 |
108th |
| 109th |
33 |
Elected in 2004.Resigned to become U.S. President. |
Jan 3, 2005 – Nov 16, 2008 |
Democratic |
 Barack Obama |
28 |
| 110th |
| |
Nov 16, 2008 – Jan 12, 2009 |
Vacant |
| Re-elected in 2008. |
33 |
111th |
| Appointed to continue Obama's term, certified late.Retired when successor qualified. |
Jan 12, 2009 – Nov 29, 2010 |
Democratic |
 Roland Burris |
29 |
| Elected to finish Obama's term.[c] |
Nov 29, 2010 – Jan 3, 2017 |
Republican |
 Mark Kirk |
30 |
| 112th |
34 |
Elected to full term in 2010.[c]Lost re-election. |
| 113th |
| Re-elected in 2014. |
34 |
114th |
| 115th |
35 |
Elected in 2016. |
Jan 3, 2017 – present |
Democratic |
 Tammy Duckworth |
31 |
| 116th |
| Re-elected in 2020.Retiring at the end of term. |
35 |
117th |
| 118th |
36 |
Re-elected in 2022. |
| 119th |
| To be determined in the 2026 election. |
36 |
120th |
| 121st |
37 |
To be determined in the 2028 election. |
| # |
Senator |
Party |
Years in office |
Electoral history |
T |
C |
T |
Electoral history |
Years in office |
Party |
Senator |
# |
| Class 2 |
Class 3 |