Harstad (Norwegian: [hɑ̂ʂtɑ] ; Northern Sami: Hárstták) is a city in Harstad Municipality in Troms county, Norway. The city is also the administrative centre of Harstad Municipality. The 11.46-square-kilometre (2,830-acre) city has a population (2023) of 21,289 (31,404 in the Urban area) and a population density of 1,858 inhabitants per square kilometre (4,810/sq mi). It is the second-largest town in Troms county, after the city of Tromsø, and it is the largest town in Central Hålogaland.
The town is located on the northeastern part of the large island of Hinnøya, along the Vågsfjorden. The city is made up of several areas (bydeler) including Gansås, Grønnebakkan, Kanebogen, Medkila, Sama, Seljestad, Stangnes, and Trondenes and more. There are two churches of the Church of Norway in the town: Harstad Church and Kanebogen Church. The historic Trondenes Church lies on the north edge of the town, near the Trondenes Fort.