Welwyn Hatfield is a local government district with borough status in the county of Hertfordshire, England. Its council is based in Welwyn Garden City. The borough borders Hertsmere, St Albans, North Hertfordshire, East Hertfordshire, Broxbourne, and the London Borough of Enfield.

Welwyn Garden City is a town in Hertfordshire, England, 20 miles (32 km) north of London. It was the second garden city in England and one of the first new towns. It is unique in being both a garden city and a new town and exemplifies the physical, social and cultural planning ideals of the periods in which it was built.