The 8th congressional district of Illinois is a congressional district in the U.S. state of Illinois that has been represented by Democrat Raja Krishnamoorthi since 2017.

The congressional district covers parts of Cook County, DuPage County and Kane County, as of the 2011 redistricting which followed the 2010 United States census. All or parts of Addison, Arlington Heights, Barrington Hills, Bloomingdale, Carol Stream, Carpentersville, East Dundee, Elgin, Elk Grove Village, Glendale Heights, Hanover Park, Hoffman Estates, Lombard, Palatine, Rolling Meadows, Roselle, Schaumburg, South Elgin, Streamwood, Villa Park and Wood Dale are included. These boundaries became effective on January 3, 2013.

#	County	Seat	Population
31	Cook	Chicago	5,087,072
43	DuPage	Wheaton	921,213
89	Kane	Geneva	514,982

• Chicago – 2,665,039
• Elgin – 114,797
• Schaumburg – 78,723
• Arlington Heights – 77,676
• Palatine – 67,908
• Des Plaines – 60,675
• Mount Prospect – 56,852
• Hoffman Estates – 52,530
• Barlett – 41,105
• Carol Stream – 39,854
• Streamwood – 39,577
• Carpentersville – 39,983
• Hanover Park – 37,470
• Addison – 35,702
• Glendale Heights – 33,176
• St. Charles – 33,081
• Elk Grove Village – 32,812
• Algonquin – 29,700
• Glen Ellyn – 28,846
• Huntley – 28,008
• Batavia – 26,098
• Rolling Meadows – 24,200
• South Elgin – 23,865
• Roselle – 22,897
• Bloomingdale – 22,382
• Geneva – 21,393
• Norridge – 15,251
• Wood Dale – 14,012
• Pingree Grove – 10,365

• Itasca – 9,543
• Gilberts – 8,366
• West Dundee – 7,686
• Hampshire – 7,667
• Inverness – 7,616
• South Barrington – 5,077
• Barrington Hills – 4,114
• Rosemont – 3,952
• Sleepy Hollow – 3,214
• East Dundee – 3,152

As of the 2020 redistricting, this district will still be based partially in northern Cook County, and now parts of northern DuPage County and northeast Kane County, as well as part of the Chicago neighborhood of O'Hare.

The 8th district takes in the Cook County communities of Schaumburg (shared with DuPage County), Rosemont, Rolling Meadows, South Barrington, and East Dundee (shared with Kane County); most of Hoffman Estates, Streamwood, and Elgin (shared with Kane County); half of Des Plaines; the majority of Elk Grove Village west of Tome Rd (shared with DuPage County); part of Palatine, Norridge, Rosemont, Arlington Heights, Hanover Park (shared with DuPage County), and Inverness; and part of Mount Prospect between Dempster St and W Lonnquist Blvd.

DuPage County is split between this district and the 3rd district. They are partitioned by Bartlett Rd, Old Wayne Golf Course, St Charles Rd, Fair Oaks Rd, Timber Ln, Woodcreek Ln N, Wayne Oaks Dam Reservoir, Morton Rd, Pawnee Dr, County Farm Rd, Highway 64, Gary Ave Della Ave, West St, Geneva Rd, Bloomingdale's Rd, Glendale Lakes Golf Club, President St, Gilberto St, Schubert Ave, Opal Ave, Stevenson Dr, Highway 4, Polo Club Dr, Canadian National Railway, East Branch Park, Army Trail Rd, Belmont Pl, Addison Trail High School, Woodland Ave, 7th Ave, Lake St, 3rd Ave, Eggerding Dr, Mill Rd, Highway 290, Addison Rd, Oak Meadows Golf & Banquets, Central Ave, Canadian Pacific Railway, Wood Dale Rd, Elmhurt St, and Lively Blvd. The 8th district takes in the communities of Bloomingdale, Schaumburg (shared with Cook County), Roselle, and Itasca; most of Carol Stream; the majority of Elk Grove Village west of Tome Rd (shared with DuPage County); part of Hanover Park (shared with Cook County); eastern Bartlett; western Wood Dale; northwestern Addison; part of Glen Ellyn; and part of northern Glendale Heights.

Kane County is split between this district and the 11th district. They are partitioned by Illinois Highway 47, Regency Parkway, Farm Hill Dr, Del Webb Blvd, Jane Adams Memorial Tollway, Sandwald Rd, Ridgecrest Dr, Brier Hill Rd/Illinois Highway 47, Coombs Rd, Shadow Hill Dr, Campton Hills Dr, West Main St, South Tyler Rd, Division St, Fox River, North Washington Ave, Douglas Rd, Orion Rd, and East Fabyan Parkway. The 8th district takes in the communities of East Dundee (shared with Cook County), West Dundee, Carpentersville, Sleepy Hollow, South Elgin, Gilberts, Pingree Grove; most of Elgin (shared with Cook County); half of St. Charles; southern Algonquin; western Wayne and Barrington Hills; eastern Hampshire; southeastern Huntley; a portion of Geneva east of the Fox River; and part of Batavia.

This table indicates how the district has voted in U.S. presidential elections; election results reflect voting in the district as it was configured at the time of the election, not as it is configured today.

Year	Office	Results
2000	President	George W. Bush 55% – Al Gore 42%
2004	President	George W. Bush 55% – John Kerry 44%
2008	President	Barack Obama 56% – John McCain 43%
2012	President	Barack Obama 58% – Mitt Romney 41%
2016	President	Hillary Clinton 58% – Donald Trump 36%
2020	President	Joe Biden 59% – Donald Trump 39%

This table indicates how the district has voted in recent statewide elections; election results reflect voting in the district as it is currently configured, not necessarily as it was at the time of these elections.

Year	Office	Results
2016	President	Hillary Clinton 54.6% – Donald Trump 38.9%
	Senate	Tammy Duckworth 52.4% – Mark Kirk 41.6%
2018	Governor	J. B. Pritzker 51.0% – Bruce Rauner 43.0%
	Attorney General	Kwame Raoul 53.3% – Erika Harold 44.1%
	Secretary of State	Jesse White 66.5% – Jason Helland 30.8%
2020	President	Joe Biden 56.8% – Donald Trump 41.4%
	Senate	Dick Durbin 55.2% – Mark Curran 39.8%
2022	Senate	Tammy Duckworth 56.3% – Kathy Salvi 42.1%
	Governor	J. B. Pritzker 55.1% – Darren Bailey 42.1%
	Attorney General	Kwame Raoul 54.8% – Tom DeVore 43.2%
	Secretary of State	Alexi Giannoulias 55.0% – Dan Brady 43.1%

Name	Party	Years	Cong– ress	Electoral history	Counties
District created March 4, 1853.
William Henry Bissell (Belleville)	Independent Democratic	March 4, 1853 – March 3, 1855	33rd	Redistricted from the 1st district and re-elected in 1852. Retired.	1853–1863 [data missing]
Vacant		March 4, 1855 – November 4, 1856	34th	Representative-elect Lyman Trumbull was elected to the U.S. Senate on February 8, 1855.
James L. D. Morrison (McLeansboro)	Democratic	November 4, 1856 – March 3, 1857	34th	Elected to finish Trumbull's term. Retired.
Robert Smith (Alton)	Democratic	March 4, 1857 – March 3, 1859	35th	Elected in 1856. Lost renomination.
Philip B. Fouke (Belleville)	Democratic	March 4, 1859 – March 3, 1863	36th 37th	Elected in 1858. Re-elected in 1860. Retired.
John T. Stuart (Springfield)	Democratic	March 4, 1863 – March 3, 1865	38th	Elected in 1862. Lost re-election.	1863–1873 DeWitt, Livingston, Logan, McLean, Sangamon, Tazewell, and Woodford
Shelby Moore Cullom (Springfield)	Republican	March 4, 1865 – March 3, 1871	39th 40th 41st	Elected in 1864. Re-elected in 1866. Re-elected in 1868. Retired.
James Carroll Robinson (Springfield)	Democratic	March 4, 1871 – March 3, 1873	42nd	Elected in 1870. Redistricted to the 12th district.
Greenbury L. Fort (Lacon)	Republican	March 4, 1873 – March 3, 1881	43rd 44th 45th 46th	Elected in 1872. Re-elected in 1874. Re-elected in 1876. Re-elected in 1878. Retired.	1873–1883 Ford, Iroquois, Kankakee, Livingston, Marshall, and Woodford
Lewis E. Payson (Pontiac)	Republican	March 4, 1881 – March 3, 1883	47th	Elected in 1880. Redistricted to the 9th district.
William Cullen (Ottawa)	Republican	March 4, 1883 – March 3, 1885	48th	Redistricted from the 7th district and re-elected in 1882. Lost renomination.	1883–1895 DuPage, Grundy, Kendall, LaSalle, and Will
Ralph Plumb (Streator)	Republican	March 4, 1885 – March 3, 1889	49th 50th	Elected in 1884. Re-elected in 1886. Retired.
Charles A. Hill (Joliet)	Republican	March 4, 1889 – March 3, 1891	51st	Elected in 1888. Lost re-election.
Lewis Steward (Plano)	Democratic	March 4, 1891 – March 3, 1893	52nd	Elected in 1890. Lost re-election.
Robert A. Childs (Hinsdale)	Republican	March 4, 1893 – March 3, 1895	53rd	Elected in 1892. Retired.
Albert J. Hopkins (Aurora)	Republican	March 4, 1895 – March 3, 1903	54th 55th 56th 57th	Redistricted from the 5th district and re-elected in 1894. Re-elected in 1896. Re-elected in 1898. Re-elected in 1900. Retired to run for U.S. senator.	1895–1903 DeKalb, DuPage, Grundy, Kane, Kendall, and McHenry
William F. Mahoney (Chicago)	Democratic	March 4, 1903 – December 27, 1904	58th	Redistricted from the 5th district and re-elected in 1902. Died.	1903–1913 Cook
Vacant		December 27, 1904 – March 3, 1905	58th
Charles McGavin (Chicago)	Republican	March 4, 1905 – March 3, 1909	59th 60th	Elected in 1904. Re-elected in 1906. Retired.
Thomas Gallagher (Chicago)	Democratic	March 4, 1909 – March 3, 1921	61st 62nd 63rd 64th 65th 66th	Elected in 1908. Re-elected in 1910. Re-elected in 1912. Re-elected in 1914. Re-elected in 1916. Re-elected in 1918. Retired.
					1913–1949 Cook
Stanley H. Kunz (Chicago)	Democratic	March 4, 1921 – March 3, 1931	67th 68th 69th 70th 71st	Elected in 1920. Re-elected in 1922. Re-elected in 1924. Re-elected in 1926. Re-elected in 1928. Lost re-election.
Peter C. Granata (Chicago)	Republican	March 4, 1931 – April 5, 1932	72nd	Lost contested election.
Stanley H. Kunz (Chicago)	Democratic	April 5, 1932 – March 3, 1933	72nd	Won contested election. Lost renomination.
Leo Kocialkowski (Chicago)	Democratic	March 4, 1933 – January 3, 1943	73rd 74th 75th 76th 77th	Elected in 1932. Re-elected in 1934. Re-elected in 1936. Re-elected in 1938. Re-elected in 1940. Lost renomination.
Thomas S. Gordon (Chicago)	Democratic	January 3, 1943 – January 3, 1959	78th 79th 80th 81st 82nd 83rd 84th 85th	Elected in 1942. Re-elected in 1944. Re-elected in 1946. Re-elected in 1948. Re-elected in 1950. Re-elected in 1952. Re-elected in 1954. Re-elected in 1956. Retired.
					1949–1953 Cook
					1953–1963 Cook
Dan Rostenkowski (Chicago)	Democratic	January 3, 1959 – January 3, 1993	86th 87th 88th 89th 90th 91st 92nd 93rd 94th 95th 96th 97th 98th 99th 100th 101st 102nd	Elected in 1958. Re-elected in 1960. Re-elected in 1962. Re-elected in 1964. Re-elected in 1966. Re-elected in 1968. Re-elected in 1970. Re-elected in 1972. Re-elected in 1974. Re-elected in 1976. Re-elected in 1978. Re-elected in 1980. Re-elected in 1982. Re-elected in 1984. Re-elected in 1986. Re-elected in 1988. Re-elected in 1990. Redistricted to the 5th district.
					1963–1967 Cook
					1967–1973 Cook
					1973–1983 Cook
					1983–1993 Cook
Phil Crane (Wauconda)	Republican	January 3, 1993 – January 3, 2005	103rd 104th 105th 106th 107th 108th	Redistricted from the 12th district and re-elected in 1992. Re-elected in 1994. Re-elected in 1996. Re-elected in 1998. Re-elected in 2000. Re-elected in 2002. Lost re-election.	1993–2003 Cook and Lake
					2003–2013 Cook, Lake, and McHenry
Melissa Bean (Barrington)	Democratic	January 3, 2005 – January 3, 2011	109th 110th 111th	Elected in 2004. Re-elected in 2006. Re-elected in 2008. Lost re-election.
Joe Walsh (McHenry)	Republican	January 3, 2011 – January 3, 2013	112th	Elected in 2010. Lost re-election.
Tammy Duckworth (Hoffman Estates)	Democratic	January 3, 2013 – January 3, 2017	113th 114th	Elected in 2012. Re-elected in 2014. Retired to run for U.S. senator.	2013–2023 Cook, DuPage, and Kane
Raja Krishnamoorthi (Schaumburg)	Democratic	January 3, 2017 – present	115th 116th 117th 118th	Elected in 2016. Re-elected in 2018. Re-elected in 2020. Re-elected in 2022.
					2023–present Cook, DuPage, and Kane

Incumbent Representative Joe Walsh was drawn out of the district for 2012 by 2011 redistricting, although a candidate is not required to live in the district to be eligible to run for a seat in Congress. Democrat Raja Krishnamoorthi of Hoffman Estates announced his candidacy for the seat in late May 2011. In July 2011, Democrat Tammy Duckworth also announced plans to run for the seat. Duckworth won the Democratic nomination on March 20, 2012. Duckworth defeated Walsh in the general election on November 6, 2012.

Illinois's 8th congressional district, 2012

Party		Candidate	Votes	%
	Democratic	Tammy Duckworth	123,206	54.7
	Republican	Joe Walsh (incumbent)	101,860	45.3
Total votes			225,066	100.0
	Democratic gain from Republican

Illinois's 8th congressional district, 2014

Party		Candidate	Votes	%
	Democratic	Tammy Duckworth (incumbent)	84,178	55.7
	Republican	Larry Kaifesh	66,878	44.3
Total votes			151,056	100.0
	Democratic hold

Illinois's 8th congressional district, 2016

Party		Candidate	Votes	%
	Democratic	Raja Krishnamoorthi	144,954	58.3
	Republican	Pete DiCianni	103,617	41.7
Total votes			248,571	100.0
	Democratic hold

Illinois's 8th congressional district, 2018

Party		Candidate	Votes	%
	Democratic	Raja Krishnamoorthi (incumbent)	130,054	66.0
	Republican	Jitendra "JD" Diganvker	67,073	34.0
Total votes			197,127	100.0
	Democratic hold

Illinois's 8th congressional district, 2020

Party		Candidate	Votes	%	±%
	Democratic	Raja Krishnamoorthi (incumbent)	186,251	73.16	+7.19%
	Libertarian	Preston Gabriel Nelson	68,327	26.84	N/A
Total votes			254,578	100.0
	Democratic hold

Illinois's 8th congressional district, 2022

Party		Candidate	Votes	%
	Democratic	Raja Krishnamoorthi (incumbent)	117,880	56.89
	Republican	Chris Dargis	89,335	43.11
Total votes			207,215	100.0
	Democratic hold

• Illinois's congressional districts
• List of United States congressional districts

• Martis, Kenneth C. (1989). The Historical Atlas of Political Parties in the United States Congress. New York: Macmillan Publishing Company.
• Martis, Kenneth C. (1982). The Historical Atlas of United States Congressional Districts. New York: Macmillan Publishing Company.
• Congressional Biographical Directory of the United States 1774–present

• Washington Post page on the 8th District of Illinois
• U.S. Census Bureau - 8th District Fact Sheet Archived September 28, 2011, at the Wayback Machine
• OpenSecrets.org political contributions and spending
• CBS county-by-county return of 2006 votes

42°00′35″N 88°05′48″W / 42.00972°N 88.09667°W / 42.00972; -88.09667