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, Pennsylvania, has about 42,000 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 criminal records, Union County court records, Pennsylvania arrest records and Pennsylvania inmate search.
Finding Someone in Custody in Union County
The county jail, run by the Union County Sheriff's Office, holds everyone kept in custody after an arrest in Union County, from every agency.
SearchSystems opened and checked the jail page of the Union County Sheriff's Office at unioncountypa.org/departments/sheriff/sheriff-s-office/page.aspx (page title: Sheriff's Office | Union County Commissioners), 103 S. Second Street Lewisburg, PA 17837, 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.
The Union County Jail by the Numbers
On an average day in 2023 the jail held about 46 people, up from about 28 in 2019. Its rated capacity in 2023 was 45 beds, and it ran at 102 percent of it that year. The figures are from the Vera Institute of Justice's Incarceration Trends data.
Union County has about 42,000 residents (2024 Census Bureau estimate), so the jail holds about 11 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 Mifflinburg and New Berlin make the arrests that end in a booking in Union County.
The FBI's agency list also places one campus police department, one state police unit and four state agencies in Union County (the arrest records guide names each one).
The largest arrest counts reported to the FBI were Buffalo Valley Regional's 222 for 2023, Mifflinburg's 64 for 2025 and New Berlin's 8 for 2025.
Together, the three agencies in Union County with all twelve months of 2025 on file reported 72 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
A sentence of more than a year is served in state prison, not the jail; the Pennsylvania Department of Corrections lists its inmates at inmatelocator.cor.pa.gov.
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 unioncountypa.org.
How many people are in the Union County jail?
About 46 on an average day in 2023, the latest year in the Vera Institute's jail data, against a rated capacity of 45 beds.
Where do people sentenced to prison in Union County go?
To a facility of the Pennsylvania Department of Corrections; its inmate locator is at inmatelocator.cor.pa.gov.
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.