Barrow-in-Furness is a port town and civil parish in the Westmorland and Furness district, in the ceremonial county of Cumbria, England. Historically in Lancashire, it was incorporated as a municipal borough in 1867 and merged with Dalton-in-Furness Urban District in 1974 to form the Borough of Barrow-in-Furness. In 2023, the borough merged with Eden and South Lakeland districts to form a new unitary authority: Westmorland and Furness. At the tip of the Furness peninsula, close to the Lake District, it is bordered by Morecambe Bay, the Duddon Estuary and the Irish Sea. In 2021, Barrow's population was 55,489, making it the second largest urban area in Cumbria after Carlisle, and the largest in the Westmorland and Furness unitary authority.

Furness is a peninsula and region of Cumbria, England. Together with the Cartmel Peninsula it forms North Lonsdale, historically an exclave of Lancashire. On 1 April 2023 it became part of the new unitary authority of Westmorland and Furness.