Oak Brook, Illinois
Oak Brook is a village in DuPage County (100% of residents) and Cook County (0.3%), Illinois, with 8,184 residents in 2020. It spans 3 congressional districts: IL-04 (51%), IL-06 (49%) and IL-07 (0.3%). It spans 2 state senate and 2 state house districts.
County
| County | Share of residents |
|---|---|
| DuPage County | 100% |
| Cook County | 0.3% |
Congressional districts
| Congressional district | Share of residents |
|---|---|
| Illinois's 4th congressional district (IL-04) | 51% |
| Illinois's 6th congressional district (IL-06) | 49% |
| Illinois's 7th congressional district (IL-07) | 0.3% |
Elected officials
| Office | Member | Contact | Share of residents |
|---|---|---|---|
| U.S. Representative (IL-04) | Jesús G. "Chuy" García (D) | 202-225-8203 | 51% |
| U.S. Representative (IL-06) | Sean Casten (D) | 202-225-4561 | 49% |
| U.S. Representative (IL-07) | Danny K. Davis (D) | 202-225-5006 | 0.3% |
| U.S. Senator | Richard J. Durbin (D) | 202-224-2152 · contact form | statewide |
| U.S. Senator | Tammy Duckworth (D) | 202-224-2854 · contact form | statewide |
| State Senator (State Senate District 23) | Suzy Glowiak Hilton (Democratic) | 630-785-3177 | 70% |
| State Senator (State Senate District 4) | Kimberly Lightford (Democratic) | 708-632-4500 | 30% |
| State Representative (State House District 45) | Marti Deuter (Democratic) | 630-413-1080 | 70% |
| State Representative (State House District 7) | Chris Welch (Democratic) | 708-450-1000 | 30% |
Officials serving now (members of Congress until January 3, 2027). Sources: State legislators: Open States (public domain); Members of Congress: the @unitedstates project, congress-legislators (CC0).
Local government
- Oak Brook website: http://www.oak-brook.org/
- Oak Brook laws: search for the Oak Brook, Illinois code of ordinances
- DuPage County website: https://www.dupagecounty.gov/
- DuPage County laws: search for the DuPage County, Illinois code of ordinances
- Cook County website: https://www.cookcountyil.gov/
- Cook County laws: search for the Cook County, Illinois code of ordinances
State legislative districts
| State senate district | Share of residents |
|---|---|
| State Senate District 23 | 70% |
| State Senate District 4 | 30% |
| State house district | Share of residents |
|---|---|
| State House District 45 | 70% |
| State House District 7 | 30% |
ZIP codes
Percentages mark ZIPs only partly in Oak Brook: the share of that ZIP's residents living in it.
Get this in your AI agent
Your agent can get Oak Brook's counties and districts with shares, its ZIP codes (level='zcta'), and its boundary as GeoJSON (get_boundaries). Add https://boundarymcp.com/mcp to Claude, ChatGPT, Cursor or Codex (free, no key; how), then:
related_geographies(id="us:place:1754534")
Oak Brook here is the Census Bureau's place boundary as of January 1, 2025. Shares are of 2020 Census population. Districts are the maps in force for the November 3, 2026 election.