Hertford is the county town of Hertfordshire, England, and is also a civil parish in the East Hertfordshire district of the county. The parish had a population of 26,783 at the 2011 census.

Hertford Castle was built in Norman times beside the River Lea in Hertford, the county town of Hertfordshire, England. Most of the internal buildings of the castle have been demolished. The main surviving section is the Tudor gatehouse, which is a Grade I listed building. Parts of the bailey walls on the east side of the castle also still stand, and are a Grade II* listed building.