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. The jail figures are from the Vera Institute of Justice's Incarceration Trends data. Every office link was opened and checked against the office's own site between September 23, 2026 and October 4, 2026.
Union County, Ohio, has about 72,000 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, the jail, who books people, state prison and common questions.
Related guides: Union County public records, Union County arrest records, Union County warrants, Union County police reports, Union County property records, Ohio arrest records and Ohio 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 unioncountyohio.gov/sheriff (page title: Union County, Ohio | Sheriff), phone 937-645-4110, 911 Location 221 West 5th Street Marysville, OH 43040, which answered when SearchSystems opened it on October 4, 2026.
That page is the office's jail information page rather than a roster, so a search for a particular person goes through the office at 937-645-4110.
The Union County Jail by the Numbers
On an average day in 2023 the jail held about 66 people, down from about 81 in 2019. Its rated capacity in 2023 was 74 beds, and it ran at 89 percent of it that year. The figures are from the Vera Institute of Justice's Incarceration Trends data.
Union County has about 72,000 residents (2024 Census Bureau estimate), so the jail holds about 9 people for every 10,000 residents.
Who Books People Into the Union County Jail
The Union County Sheriff's Office and the agencies that report for Marysville and Richwood make the arrests that end in a booking in Union County.
The Plain City Police Department and the Dublin Police Department are each listed by the FBI across several counties including Union County, so their arrests are not broken out for Union County here.
The largest arrest counts reported to the FBI were Marysville's 185 for 2025, the Union County Sheriff's Office's 86 for 2025 and Richwood's 13 for 2023.
Together, the two agencies in Union County with all twelve months of 2025 on file reported 271 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 Ohio Department of Rehabilitation and Correction, whose inmate locator is at appgateway.drc.ohio.gov/OffenderSearch.
Frequently Asked Questions
How do I find an inmate in Union County?
Ask the Union County Sheriff's Office at 937-645-4110; its jail page SearchSystems verified is at unioncountyohio.gov/sheriff.
How many people are in the Union County jail?
About 66 on an average day in 2023, the latest year in the Vera Institute's jail data, against a rated capacity of 74 beds.
What is the phone number for the Union County jail?
937-645-4110, the number on the page of the Union County Sheriff's Office SearchSystems verified.
Where do people sentenced to prison in Union County go?
To a facility of the Ohio Department of Rehabilitation and Correction; its inmate locator is at appgateway.drc.ohio.gov/OffenderSearch.
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.