Harpenden is a town and civil parish in the City and District of St Albans in the county of Hertfordshire, England. The population of the built-up area was 30,674 in the 2021 census, while the population of the civil parish was 31,128. Harpenden is a commuter town, with a direct rail connection to Central London.

St Albans, also known as the City and District of St Albans, is a local government district with city status in Hertfordshire, England. Its council is based in St Albans, the largest settlement in the district. The district also includes the town of Harpenden and several villages. The district borders North Hertfordshire, Welwyn Hatfield, Hertsmere, Watford, Three Rivers, Dacorum, and Central Bedfordshire.