Northwest (Icelandic: Norðvestur) is one of the six multi-member constituencies of the Althing, the national legislature of Iceland. The constituency was established as Northwestern (Icelandic: Norðurland vestra) in 1959 following the nationwide extension of proportional representation for elections to the Althing. It was renamed Northwest in 2003 when the Western and Westfjords constituencies were merged into the Northwestern constituency following the re-organisation of constituencies across Iceland. Northwest consists of the regions of Northwestern, Western and Westfjords. The constituency currently elects seven of the 63 members of the Althing using the open party-list proportional representation electoral system. At the 2021 parliamentary election it had 21,541 registered electors.

Northwest currently elects seven of the 63 members of the Althing using the open party-list proportional representation electoral system.^[4][5] Constituency seats are allocated using the D'Hondt method.^[6][7] Compensatory seats (equalisation seas) are calculated based on the national vote and are allocated using the D'Hondt method at the constituency level.^[8][9] Only parties that reach the 5% national threshold compete for compensatory seats.^[7][10]