Hitchin is a market town in the North Hertfordshire district of Hertfordshire, England. The town dates from at least the 7th century. It lies in the valley of the River Hiz at the north-eastern end of the Chiltern Hills. It is 16 miles north-west of the county town of Hertford, and 35 miles north of London. The population at the 2021 census was 35,220.