Reviewed and updated October 9, 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 between September 23, 2026 and October 4, 2026.
Union County, Illinois, has about 17,000 residents (2024 Census Bureau estimate). A person kept in custody after an arrest in Union County is held at the county jail, run by the Union County Sheriff's Office, and the jail's record of each person held is a public record. This guide says where to look for someone in custody, what the jail holds and who books people into it.
This guide covers the search, who books people, state prison and common questions.
Related guides: Union County public records, Union County arrest records, Union County warrants, Union County criminal records, Union County court records, Illinois arrest records and Illinois inmate search.
Finding Someone in Custody in Union County
A person kept in custody after an arrest in Union County is held at the county jail, run by the Union County Sheriff's Office, whichever agency made the arrest.
SearchSystems opened and checked the jail page of the Union County Sheriff's Office at ilsheriff.org/county/union (page title: Union County | Illinois Sheriffs' Association), a site that blocks automated checks (HTTP 403), so open it in a browser.
That page is the office's jail information page rather than a roster.
Who Books People Into the Union County Jail
The Union County Sheriff's Office and the agencies that report for Anna, Jonesboro, Cobden and Dongola make the arrests that end in a booking in Union County.
The largest arrest counts reported to the FBI were Dongola's 1,152 for 2025, Cobden's 1,152 for 2025 and Jonesboro's 1,152 for 2025.
Together, the four agencies in Union County with all twelve months of 2025 on file reported 3,533 arrests to the FBI that year. Those kept in custody were booked into the county jail; a person cited and released at the scene was not.
The counts, agency by agency and year by year, are in Union County arrest records.
From the Jail to State Prison
The jail holds people awaiting trial and people serving short sentences. A person sentenced to prison in Union County serves the sentence in a facility of the Illinois Department of Corrections, whose inmate locator is at idoc.illinois.gov/offender/inmatesearch.html.
Frequently Asked Questions
How do I find an inmate in Union County?
Ask the Union County Sheriff's Office; its jail page SearchSystems verified is at ilsheriff.org/county/union.
Where do people sentenced to prison in Union County go?
To a facility of the Illinois Department of Corrections; its inmate locator is at idoc.illinois.gov/offender/inmatesearch.html.
Is this the official Union 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.