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 24, 2026 and September 26, 2026.
Ontario, Oregon, in Malheur County, has about 12,000 residents (2024 Census Bureau estimate). A person kept in custody after an arrest in Ontario is held at the county jail, run by the Malheur 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: Ontario public records, Malheur County inmate search, Ontario arrest records, Ontario warrants, Ontario criminal records, Ontario court records, Oregon arrest records and Oregon inmate search.
Finding Someone in Custody in Ontario
A person kept in custody after an arrest in Ontario is held at the county jail, run by the Malheur County Sheriff's Office, whichever agency made the arrest.
SearchSystems opened and checked the jail page of the Malheur County Sheriff's Office at sheriff.malheurco.org (page title: MALHEUR COUNTY SHERIFF’S OFFICE | Our Mission: Provide public safety services to our community with a professi), which answered when SearchSystems opened it on September 24, 2026.
That page is the office's jail information page rather than a roster.
The Malheur County Jail by the Numbers
On an average day in 2023 the jail held about 72 people, up from about 72 in 2019. Its rated capacity in 2019, the last year with a capacity figure, was 91 beds, and it ran at 79 percent of it that year. The figures are from the Vera Institute of Justice's Incarceration Trends data.
Malheur County has about 32,000 residents (2024 Census Bureau estimate), so the jail holds about 22 people for every 10,000 residents.
Who Books People Into the Malheur County Jail
The Malheur County Sheriff's Office and the agency that reports for Ontario (filed by the FBI as Ontario Police Department) make the arrests that end in a booking in and around Ontario.
The FBI's agency list also places these agencies in Malheur County: the Malheur County Liquor Commission (state agency); the Malheur County State Police (state police).
The largest arrest counts reported to the FBI were Ontario's 658 for 2025, the Malheur County Sheriff's Office's 497 for 2024 and Nyssa's 47 for 2023.
Together, the two agencies in Malheur County with all twelve months of 2024 on file reported 1,132 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 Ontario arrest records.
From the Jail to State Prison
A sentence of more than a year is served in state prison, not the jail; the Oregon Department of Corrections lists its inmates at oregon.gov/doc/victim-services/pages/offender-search.aspx.
Frequently Asked Questions
How do I find an inmate in Ontario?
Ask the Malheur County Sheriff's Office; its jail page SearchSystems verified is at sheriff.malheurco.org.
How many people are in the Malheur County jail?
About 72 on an average day in 2023, the latest year in the Vera Institute's jail data, against a rated capacity of 91 beds.
Where do people sentenced to prison in Malheur County go?
To a facility of the Oregon Department of Corrections; its inmate locator is at oregon.gov.
Is this the official Ontario website?
No. SearchSystems.net is an independent public records guide, online since 1997. It links to the official city, county, court and state offices described above and does not hold records, charge for them or take requests.