The Old Gaol, also known as the Manor Office, is a custodial building in Hallgate in Hexham, Northumberland, England.

It was designed in the Medieval style, built in rubble masonry and was completed in January 1332.

[9] The old gaol became the home of the 2nd Northumberland Rifle Volunteers when it was formed in 1860 and remained in use as such until Hencotes drill hall was completed in 1891.

Topics covered include archaeology, archives, costume and textiles, law and order, music, photography, social history, weapons and war.

The collections include 15th and 16th century arms and armour, and objects of local historical interest.