Harlow is a town and local government district located in the west of Essex, England. Harlow was a small town until the mid-20th century. In 1947 it was designated as a new town. Housing estates, industrial areas and a new town centre were subsequently developed, lying mostly to the west and south of the old town, which became known as Old Harlow.
The town lies on the south bank of the River Stort, which also forms the county boundary with Hertfordshire. The M11 motorway passes to the east of the town. At the 2021 census the Harlow built up area had a population of 93,580 and the local government district had a population of 93,300.