Reviewed and updated October 7, 2026 by the SearchSystems.net editorial team. The arrest counts are the ones each agency reported to the FBI, as the FBI held them on October 8, 2026. Every office link was opened and checked against the office's own site on September 23, 2026.
Cook County, Illinois, has about 5.2 million residents (2024 Census Bureau estimate). Its court cases are filed in the Circuit Court of Cook County, and the file of each case, kept by the Circuit Clerk, is the public record of it. This guide says which court hears what, where to look a case up and who keeps the files.
This guide covers the courts, the records page, criminal cases, kinds of files, cities and common questions.
Related guides: Cook County public records, Cook County warrants, Cook County inmate search, Cook County criminal records, Cook County police reports, Illinois arrest records and Illinois inmate search.
The Courts That Hear Cases from Cook County
Court cases from Cook County are filed in the Circuit Court of Cook County, which hears every civil, criminal, family, probate, traffic and juvenile case.
Divorces go to the Circuit Court's domestic relations division, and the file stays with the Circuit Clerk.
The Circuit Clerk keeps the files, and a copy of anything in a file comes from that office, under the court's own rules rather than the Illinois Freedom of Information Act.
Looking Up a Case from Cook County
The court records page SearchSystems verified for the county is at cookcountyil.gov/service/court-records-and-archives (page title: Court Records and Archives), which answered when SearchSystems opened it on September 23, 2026.
Illinois has no single public index of every trial court case; each court's records are looked up through that court.
The Illinois court page SearchSystems verified is at illinoiscourts.gov.
What Reaches the Court from Cook County
Together, the 100 agencies in Cook County with all twelve months of 2025 on file reported 71,187 arrests to the FBI that year; the State's Attorney decides which of those arrests become cases in the Circuit Court of Cook County.
The State's Attorney's page SearchSystems verified is at cookcountyil.gov/agency/states-attorney (page title: States Attorney), phone (312) 603-1880, which answered when SearchSystems opened it on September 23, 2026.
The Kinds of Court Files
Criminal cases, divorces, traffic tickets and evictions all end up as files of these courts, and the file is what the public sees of each.
The other Cook County guides take the kinds of file one at a time: Cook County criminal records, Cook County divorce records, Cook County traffic tickets, Cook County DUI and Cook County property records.
Cities in Cook County
Wherever in the county a case arises, it is filed in the Circuit Court of Cook County.
SearchSystems has a guide to the offices of these cities in Cook County, with the 2024 Census Bureau population:
- Chicago (2,721,308)
- Evanston (76,006)
- Arlington Heights (75,596)
- Palatine (65,951)
- Des Plaines (58,832)
- Orland Park (58,020)
- Oak Lawn (56,531)
- Mount Prospect (55,460)
- Berwyn (55,152)
- Tinley Park (54,856)
- Hoffman Estates (50,920)
- Park Ridge (38,445)
- Streamwood (38,360)
- Wheeling (38,329)
- Hanover Park (36,685)
- Calumet City (34,855)
- Northbrook (34,546)
- Niles (29,918)
- Burbank (28,606)
- Lansing (28,107)
- Wilmette (27,443)
- Oak Forest (26,813)
- Chicago Heights (26,533)
- Morton Grove (24,467)
- Elmwood Park (23,698)
- Blue Island (21,805)
- Park Forest (21,016)
- Dolton (20,697)
- Evergreen Park (19,301)
- Brookfield (18,885)
- Matteson (18,566)
- Alsip (18,486)
- Lemont (18,203)
- Bellwood (18,132)
- Franklin Park (18,110)
- Palos Hills (18,026)
- Bridgeview (16,559)
- Westchester (16,313)
- Country Club Hills (16,238)
- Prospect Heights (15,566)
Frequently Asked Questions
How do I look up a court case in Cook County?
The court records page SearchSystems verified for the county is at cookcountyil.gov.
Which court hears felonies in Cook County?
The Circuit Court of Cook County, which hears every civil, criminal, family, probate, traffic and juvenile case.
Who keeps the court records in Cook County?
The Circuit Clerk. Copies come from that office under the court's own rules.
Is there a statewide court case search in Illinois?
No. Each court's records are looked up through that court.
Is this the official Cook County website?
No. SearchSystems.net is an independent public records guide, online since 1997. It links to the official county, court and state offices described above and does not hold records, charge for them or take requests.