Neskaupstaður is a town located on the fjord Norðfjörður on the eastern side of Iceland. It is part of the municipality of Fjarðabyggð and, as of 2016, it has a population of 1,481. Neskaupstaður is the third largest town in Eastern Region. The town was originally built on a farm called "Nes", settled by Egill rauði ("the red").

The town was nicknamed "Little Moscow" in the 20th century due its strong socialist background.

Until 1949, the town was only accessible by boat. Then it was connected through a 626-meter long single-lane tunnel that passed through the Oddskard mountains called Oddskarðsgöng. Oddskarðsgöng was 632 meters above the sea level and was built between 1974-1977. Oddskardsgöng is now closed. The town is now connected with a new 7.542-meter 2-lane tunnel called Norðfjarðargöng which was constructed between 2013-2017.

The building of an aluminum smelter and a new hydroelectric power-plant in East Iceland in 2003 reinvigorated the local economy.

Neskaupstaður joined Eskifjörður and Reyðarfjörður in 1998 to form the new municipality of Fjarðabyggð ("fjords-settlement").