The Old Gaol, also known as the Manor Office, is a custodial building in Hallgate in Hexham, Northumberland, England. The building, which now operates as a museum, is a Grade I listed building.

Hexham is a market town and civil parish in Northumberland, England, on the south bank of the River Tyne, formed by the confluence of the North Tyne and the South Tyne at Warden nearby, and close to Hadrian's Wall. Hexham was the administrative centre for the Tynedale district from 1974 to 2009. In 2011, it had a population of 13,097.