Illinois has three primary immigration detention centers, along with a handful of smaller county jails that contract with ICE to house immigrant detainees.
- Jefferson County Justice Center – Mt. Vernon, Illinois
- McHenry County Jail – Woodstock, Illinois
- Tri-County Detention Center – Ullin, Illinois
The largest of these is the Tri- County Detention Center, which houses about 215 immigration detainees on an average day. All immigration detainees in Illinois are under the jurisdictions of the Chicago Immigration Court and the Chicago ERO Field Office.