Arna is a borough in the city of Bergen in Vestland county, Norway. It is one of eight boroughs in Bergen. It encompasses the northeastern part of the municipality of Bergen. Arna was merged into the city of Bergen in 1972. Prior to that, it was the separate municipality of Arna. The main population centres in the borough are the villages of Indre Arna, Ytre Arna, and Espeland.

Bergen, historically Bjørgvin, is a city and municipality in Vestland county on the west coast of Norway. As of 2022, its population was roughly 289,330. Bergen is the second-largest city in Norway after national capital Oslo. The municipality covers 465 square kilometres (180 sq mi) and is located on the peninsula of Bergenshalvøyen. The city centre and northern neighbourhoods are on Byfjorden, 'the city fjord'. The city is surrounded by mountains, causing Bergen to be called the "city of seven mountains". Many of the extra-municipal suburbs are on islands. Bergen is the administrative centre of Vestland county. The city consists of eight boroughs: Arna, Bergenhus, Fana, Fyllingsdalen, Laksevåg, Ytrebygda, Årstad, and Åsane.