Illinois Circuit Courts by County: Locations and Jurisdictions

Illinois operates 24 judicial circuits, each composed of one or more counties, forming the backbone of the state's trial court system. These circuits handle the overwhelming majority of litigation filed in Illinois — from felony criminal prosecutions to civil contract disputes, family law matters, and probate proceedings. The geographic organization of circuit courts determines which courthouse a case enters, which local rules govern procedure, and which judges hold subject-matter authority over a given filing.

Definition and scope

Circuit courts are the general trial courts of Illinois, established under Article VI of the Illinois Constitution of 1970. All 102 Illinois counties fall within one of the 24 circuits, making circuit courts the entry point for virtually every case that enters the Illinois judicial system. The Illinois Courts website (illinoiscourts.gov) maintains the authoritative listing of circuit assignments, presiding judges, and courthouse locations for each of the 24 circuits.

Circuit courts exercise original jurisdiction over all justiciable matters unless a specific statute assigns exclusive jurisdiction elsewhere. This broad grant covers:

1. Criminal matters — felony, misdemeanor, and ordinance violations
2. Civil matters — contract, tort, and property disputes without a dollar ceiling at the circuit level (small claims proceedings, governed under Illinois Supreme Court Rule 281, are limited to $10,000)
3. Family law — dissolution of marriage, child custody, orders of protection
4. Probate — estate administration, guardianship, and conservatorship
5. Juvenile matters — delinquency, abuse and neglect, and dependency proceedings
6. Traffic and ordinance — municipal and county code enforcement

Cook County, which encompasses Chicago and 134 suburban municipalities, operates as its own single-county circuit — the Cook County Circuit Court — and is the largest unified trial court in the United States by caseload volume, according to the Administrative Office of the Illinois Courts (AOIC) annual statistical reports. The remaining 101 counties are organized into 23 multi-county circuits.

The regulatory context for the Illinois legal system addresses how state circuit court authority relates to federal court jurisdiction in matters of concurrent or exclusive federal cognizance.

Scope and coverage limitations: This page covers Illinois state circuit courts and their county-based jurisdictional assignments. It does not address federal district courts operating in Illinois (the Northern, Central, and Southern Districts), tribal courts, municipal administrative tribunals, or the circuit courts of neighboring states. Cases governed exclusively by federal subject-matter jurisdiction — such as bankruptcy, patent, and immigration removal proceedings — fall outside circuit court authority and are not covered here.

How it works

A case enters the circuit court system based on the county where the cause of action arose or where a defendant resides, following venue rules codified in the Illinois Code of Civil Procedure (735 ILCS 5/). Once filed, the clerk of the circuit court assigns the matter to a division and docket, and a judge is assigned according to local administrative orders.

Each circuit maintains its own local rules that supplement Illinois Supreme Court Rules. These local rules govern filing formats, motion schedules, and courtroom protocols. The AOIC publishes standardized forms — designated IL-AOIC forms — that function across all 24 circuits, though circuits may require additional locally mandated documents.

The adjudicative process follows a structured sequence:

1. Filing and docketing — complaint or petition filed with the clerk; filing fees assessed under 705 ILCS 105/
2. Service of process — defendant notified per Illinois Supreme Court Rules 101–107
3. Responsive pleadings — answer or motion filed within statutory deadlines
4. Discovery — governed by Illinois Supreme Court Rules 201–224
5. Pretrial motions — summary judgment, motions in limine, and other dispositive or evidentiary motions
6. Trial — bench or jury, depending on the nature of the case and parties' elections
7. Judgment and post-trial motions — including motions to reconsider under 735 ILCS 5/2-1203
8. Appeal — to the applicable Illinois Appellate Court district; reviewed under the Illinois appellate court process

For an overview of how the circuit court tier relates to appellate and supreme court authority, the Illinois court system structure page maps the full hierarchical framework.

Common scenarios

Circuit courts encounter a defined set of recurring case categories that reflect the legal needs of Illinois's approximately 12.8 million residents (U.S. Census Bureau, 2020 Decennial Census).

Domestic relations filings represent one of the highest-volume categories in most circuits. Dissolution of marriage proceedings are governed by the Illinois Marriage and Dissolution of Marriage Act (750 ILCS 5/), and custody determinations follow the allocation of parental responsibilities framework established in the 2016 amendments to that act.

Eviction and landlord-tenant matters — designated as Forcible Entry and Detainer actions under 735 ILCS 5/9-101 — constitute a substantial share of civil filings in Cook County and other urban circuits. The AOIC annual reports document tens of thousands of such filings annually in Cook County alone.

Criminal felony prosecutions are initiated in circuit court following indictment by a grand jury or the filing of an information by a State's Attorney. Each of Illinois's 102 counties has an elected State's Attorney who functions as the county's chief prosecutor before the circuit court, as established under Article VI, Section 19 of the Illinois Constitution.

Small claims proceedings — available for disputes at or below $10,000 — offer a simplified procedural track that reduces formal pleading and discovery requirements, making self-represented litigation more accessible. Illinois pro se litigant resources addresses the procedural accommodations available to unrepresented parties in these proceedings.

Illinois court fees and costs covers the specific filing fee schedules applicable to circuit court filings by case type.

Decision boundaries

Understanding which court holds authority over a given matter requires distinguishing between circuit court jurisdiction and several adjacent forums.

Circuit court vs. federal district court: Federal courts in Illinois hold exclusive jurisdiction over bankruptcy (28 U.S.C. § 1334), patent and copyright claims (28 U.S.C. § 1338), and federal criminal prosecutions. Civil matters that qualify under federal diversity jurisdiction (28 U.S.C. § 1332) — where parties are from different states and the amount in controversy exceeds $75,000 — may be filed in either forum, though removal to federal court is available to defendants. The Illinois federal courts presence page details the three federal districts operating within state boundaries.

Circuit court vs. Illinois administrative agencies: Many regulatory disputes — license revocations, agency enforcement actions, workers' compensation claims — originate before Illinois administrative agencies rather than circuit courts. Administrative decisions are then subject to circuit court review under the Illinois Administrative Review Law (735 ILCS 5/3-101 et seq.). The Illinois administrative law overview page maps this parallel track.

Circuit court vs. Illinois Appellate Court: Circuit courts are trial courts of first instance; they do not review their own decisions on appeal. Parties seeking review of a final circuit court judgment file a notice of appeal with the circuit court clerk, which then transfers the record to the appropriate appellate district. Illinois is divided into 5 appellate districts, with District 1 covering Cook County exclusively.

Multi-county circuits vs. single-county courts: In the 23 multi-county circuits, each county maintains its own courthouse and clerk's office, but cases may be transferred between counties within the same circuit by order of the presiding judge. Cook County's single-county structure means all circuit court matters for Chicago and Cook County suburbs are centralized under one administrative hierarchy, though internally divided into departments (Law, Chancery, Domestic Relations, Criminal, Probate, and others).

Practitioners and self-represented parties navigating the full spectrum of Illinois legal procedure should consult the index of this reference for the complete framework of Illinois legal system topics, including jurisdictional questions addressed in Illinois legal jurisdiction explained.

References

• Illinois Courts — illinoiscourts.gov
• Illinois Constitution of 1970, Article VI
• Illinois Compiled Statutes — Illinois General Assembly (ilga.gov)
• Illinois Code of Civil Procedure, 735 ILCS 5/
• Illinois Marriage and Dissolution of Marriage Act, 750 ILCS 5/
• Administrative Office of the Illinois Courts (AOIC)
• [Illinois Supreme Court Rules](https://www.illinoiscourts.gov/rules/supreme-court-rules