Illinois State House District 51

State Legislative District Profile (Lower Chamber)

Overview

District ID
il-hd-051
State
Illinois
Chamber
Lower chamber
District Code
051
Land Area
65.9 sq mi
Water Area
1.85 sq mi

Boundary

Boundary of Illinois State House District 51

Boundary as GeoJSON

Source: U.S. Census Bureau TIGER/Line state legislative district boundaries.

Counties

CountyOverlapShare of district landShare of county land
Lake County39.63 sq mi60.1%8.9%
Cook County26.30 sq mi39.9%2.8%

Showing all 2 counties

Places

PlaceOverlapShare of district landShare of place land
Long Grove village11.08 sq mi16.8%89.5%
Palatine village8.97 sq mi13.6%63.5%
Lake Zurich village6.87 sq mi10.4%99.2%
Hawthorn Woods village6.02 sq mi9.1%74.0%
Inverness village5.25 sq mi8.0%80.3%
Kildeer village4.23 sq mi6.4%98.1%
Hoffman Estates village4.04 sq mi6.1%19.6%
Deer Park village3.56 sq mi5.4%97.1%
Barrington village1.37 sq mi2.1%29.6%
North Barrington village0.99 sq mi1.5%21.0%
Rolling Meadows city0.85 sq mi1.3%15.1%
Schaumburg village0.58 sq mi0.9%3.0%
Forest Lake CDP0.35 sq mi0.5%99.9%
South Barrington village0.31 sq mi0.5%4.1%
Vernon Hills village0.24 sq mi0.4%3.1%
Buffalo Grove village0.13 sq mi0.2%1.4%

Showing all 16 places

Overlapping Congressional Districts

Congressional districtPopulation in bothShare of this district's populationShare of the congressional district's populationShare of this district's land
IL District 583,24276.7%11.0%67.6%
IL District 915,02413.8%2.0%23.1%
IL District 88,0597.4%1.1%6.4%
IL District 102,1642.0%0.3%2.8%

Source: U.S. Census Bureau 2020 blocks and 2025 block equivalency files (119th Congress, 2024 state legislative plans).

Voters

Registered Voters
86,097
Active Voters
80,867 (93.9%)

Party Registration

This state's voter file does not record party registration.

Turnout by Cycle

CycleGeneralDemocratic PrimaryRepublican Primary
2025–202614,347 (16.7%)0 (0.0%)<10 (—)
2023–202459,106 (68.7%)7,041 (8.2%)5,141 (6.0%)
2021–202244,960 (52.2%)9,730 (11.3%)8,013 (9.3%)
2019–202057,619 (66.9%)14,353 (16.7%)5,070 (5.9%)
2017–201843,893 (51.0%)10,371 (12.0%)8,161 (9.5%)
2015–201646,216 (53.7%)11,496 (13.4%)15,027 (17.5%)
2013–201428,915 (33.6%)1,184 (1.4%)7,382 (8.6%)
2011–201235,749 (41.5%)2,496 (2.9%)8,254 (9.6%)

Turnout counts today's registered voters with a counted ballot in the cycle's elections (the odd and even year), as a share of today's registered voters. Voters who have since left the rolls are not counted.

Browse the voter list for this district (premium access; sign-in required)

Source: Civitech voter file snapshot as of 12/15/2025. These are registered voters, separate from the Census population figures. Counts under 10 are suppressed and shown as "<10".

Demographics

Total Population
109,836 (± 1,980)
Median Age
42.7
Median Household Income
$150,083 (± $6,211)
High School Graduate or Higher (age 25+)
96.9%
Bachelor's Degree or Higher (age 25+)
63.0%

Population by Age

GroupPeopleShare
Under 1825,16922.9%
18 to 6464,88959.1%
65 and over19,77818.0%

Population by Race and Hispanic Origin

GroupPeopleShare
Hispanic or Latino (any race)7,8357.1%
White, not Hispanic80,81073.6%
Black, not Hispanic2,3362.1%
Asian, not Hispanic14,53413.2%
American Indian / Alaska Native, not Hispanic590.1%
Native Hawaiian / Pacific Islander, not Hispanic160.0%
Some other race, not Hispanic2590.2%
Two or more races, not Hispanic3,9873.6%

Source: U.S. Census Bureau, American Community Survey 2020-2024 ACS 5-year estimates (tables B01001, B01002, B01003, B03002, B15003, B19013) for this state legislative district. Estimates are survey-based; ± figures are 90% margins of error.

Citizen Voting Age Population

Total Citizen Population
103,125
Citizen Voting Age Population (CVAP)
78,768

Citizen Population by Race/Ethnicity

GroupCitizensShare
Non-Hispanic96,39393.5%
Hispanic6,7346.5%
White80,16577.7%
Black2,3072.2%
Asian10,87910.5%
American Indian / Alaska Native620.1%
Native Hawaiian / Pacific Islander170.0%
Two or More Races4520.4%

Citizen Voting Age Population by Race/Ethnicity

GroupCVAPShare
Non-Hispanic74,26294.3%
Hispanic4,5055.7%
White63,40280.5%
Black2,0712.6%
Asian8,14710.3%
American Indian / Alaska Native3770.5%
Native Hawaiian / Pacific Islander170.0%
Two or More Races2960.4%

Source: Redistricting Data Hub / U.S. Census Bureau CVAP Special Tabulation (2020-2024 ACS 5-year).