Overview
- District ID
- il-sd-055
- State
- Illinois
- Chamber
- Upper chamber (state senate)
- District Code
- 055
- Land Area
- 4,016.4 sq mi
- Water Area
- 52.9 sq mi
Boundary
Boundary as GeoJSON
Source: U.S. Census Bureau TIGER/Line state legislative district boundaries.
Counties
Showing all 11 counties
Places
Showing top 25 of 91 places
Overlapping Congressional Districts
| Congressional district | Population in both | Share of this district's population | Share of the congressional district's population | Share of this district's land |
|---|
| IL District 12 | 124,064 | 57.1% | 16.5% | 60.6% |
| IL District 15 | 92,299 | 42.5% | 12.2% | 39.2% |
| IL District 13 | 749 | 0.3% | 0.1% | 0.1% |
Source: U.S. Census Bureau 2020 blocks and 2025 block equivalency files (119th Congress, 2024 state legislative plans).
Voters
- Registered Voters
- 156,549
- Active Voters
- 152,674 (97.5%)
Party Registration
This state's voter file does not record party registration.
Turnout by Cycle
| Cycle | General | Democratic Primary | Republican Primary |
|---|
| 2025–2026 | 32,483 (20.7%) | 0 (0.0%) | 0 (0.0%) |
| 2023–2024 | 112,188 (71.7%) | 4,678 (3.0%) | 25,190 (16.1%) |
| 2021–2022 | 87,234 (55.7%) | 4,967 (3.2%) | 30,437 (19.4%) |
| 2019–2020 | 102,043 (65.2%) | 12,048 (7.7%) | 24,135 (15.4%) |
| 2017–2018 | 77,403 (49.4%) | 9,284 (5.9%) | 22,534 (14.4%) |
| 2015–2016 | 86,650 (55.4%) | 13,795 (8.8%) | 31,380 (20.0%) |
| 2013–2014 | 58,878 (37.6%) | 4,581 (2.9%) | 13,830 (8.8%) |
| 2011–2012 | 69,915 (44.7%) | 3,561 (2.3%) | 14,521 (9.3%) |
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
- 216,939 (± 1,231)
- Median Age
- 41.3
- Median Household Income
- $76,856 (± $1,671)
- High School Graduate or Higher (age 25+)
- 92.3%
- Bachelor's Degree or Higher (age 25+)
- 25.8%
Population by Age
| Group | People | Share |
|---|
| Under 18 | 48,918 | 22.5% |
| 18 to 64 | 126,574 | 58.3% |
| 65 and over | 41,447 | 19.1% |
Population by Race and Hispanic Origin
| Group | People | Share |
|---|
| Hispanic or Latino (any race) | 5,763 | 2.7% |
| White, not Hispanic | 196,578 | 90.6% |
| Black, not Hispanic | 4,719 | 2.2% |
| Asian, not Hispanic | 1,174 | 0.5% |
| American Indian / Alaska Native, not Hispanic | 410 | 0.2% |
| Native Hawaiian / Pacific Islander, not Hispanic | 35 | 0.0% |
| Some other race, not Hispanic | 684 | 0.3% |
| Two or more races, not Hispanic | 7,576 | 3.5% |
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
- 215,509
- Citizen Voting Age Population (CVAP)
- 166,734
Citizen Population by Race/Ethnicity
| Group | Citizens | Share |
|---|
| Non-Hispanic | 210,664 | 97.8% |
| Hispanic | 4,840 | 2.2% |
| White | 198,573 | 92.1% |
| Black | 4,771 | 2.2% |
| Asian | 913 | 0.4% |
| American Indian / Alaska Native | 411 | 0.2% |
| Native Hawaiian / Pacific Islander | 34 | 0.0% |
| Two or More Races | 211 | 0.1% |
Citizen Voting Age Population by Race/Ethnicity
| Group | CVAP | Share |
|---|
| Non-Hispanic | 163,774 | 98.2% |
| Hispanic | 2,964 | 1.8% |
| White | 154,847 | 92.9% |
| Black | 4,805 | 2.9% |
| Asian | 1,139 | 0.7% |
| American Indian / Alaska Native | 2,795 | 1.7% |
| Native Hawaiian / Pacific Islander | 37 | 0.0% |
| Two or More Races | 159 | 0.1% |
Source: Redistricting Data Hub / U.S. Census Bureau CVAP Special Tabulation (2020-2024 ACS 5-year).
