Home › Venues › Washington County Fairgrounds Washington County Fairgrounds Tickets Buy tickets for concerts at Washington County Fairgrounds in Hillsboro, OR. No Upcoming Events No upcoming events scheduled at Washington County Fairgrounds. Please contact us with any corrections. Hotels & Lodging Near Washington County Fairgrounds About the Venue Washington County Fairgrounds At-a-Glance Address873 NE 34th AveHillsboro, OR 97124United States Map & Directions Advertisement