Furness

upright=1.35|thumb|Furness, overlaid onto current administrative areas 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.

The Furness Peninsula, also known as Low Furness, is an area of villages, agricultural land and low-lying moorland, with the industrial town of Barrow-in-Furness at its head. The peninsula is bordered by the estuaries of the River Duddon to the west and the River Leven in Morecambe Bay to the east. The wider region of Furness consists of the peninsula and the area known as High Furness, which is a relatively mountainous and sparsely populated part of England, extending inland into the Lake District and containing the Furness Fells. The inland boundary of the region is formed by the rivers Leven, Brathay and Duddon, and the lake of Windermere. Off the southern tip of Furness is Walney Island, long, as well as several smaller islands.