Coordinates: 54°38′24″N 3°24′43″W / 54.640°N 3.412°W / 54.640; -3.412

Allerdale is a non-metropolitan district of Cumbria, England, with borough status. Its council is based in Workington and the borough has a population of 93,492 according to the 2001 census.

The Borough of Allerdale was formed under the Local Government Act 1972, on 1 April 1974 by the merger of the municipal borough of Workington, the urban districts of Maryport, Cockermouth and Keswick; and the rural districts of Cockermouth and Wigton, all of which were within the administrative county of Cumberland. In 1995 Allerdale was granted borough status.

The name derives from the ancient region of Allerdale, represented latterly by the two wards of Cumberland, called Allerdale above Derwent and Allerdale below Derwent.

Elections to the borough council are held every 4 years with 56 councillor being elected from 31 wards. No party has had a majority on the council since Labour lost their majority at the 2003 election. As of the 2011 election, and following a by-election, the council is composed of the following councillors:-