The Gud med oss (God be with us) coat-of-arms created in 1665 shows a knight standing on a mountain, yellow on a blue background, and was inspired by the bravery of the citizens of the city in the Dano-Swedish War (1658–1660).

As a reference to the town's citizens burning their own houses to prevent them being taken on 4 July 1716 by the forces of King Charles XII of Sweden, Halden is one of only two cities in Norway's national anthem.

In the late 1960s, the most powerful mainframe computer in Norway at the time was located at the Institute for Energy Technology's facilities in Halden.

[14] Petroglyphs (rock carvings) dated from the Nordic Bronze Age are found around town, some locally, but more impressive are ones found along Oldtidsveien, the historical road between Halden and Fredrikstad some 20 km (12 mi) north, and around Tanum in Sweden, some 60 km (37 mi) to the south.

Jellhaugen, a major tumulus (grave mound) is found west of town,[15] situated only 120 feet away from the site of the later discovered Gjellestad Ship.

Raspberries, blackberries, blueberries, wild cranberries, and many varieties of mushroom can be found in the woods in the early autumn.

[18] Originally interred beneath a burial mound, in the present day the ship lies 40 centimetres below the topsoil due to years of ploughing.

[19] Due to extensive fungus damage to the hull caused by field drainage, drought and exposure to the air, archaeologists called for an immediate dig to save the ship.

[20] Excavation of the ship at Gjellestad began in June 2020,[21] and is led by Christian L. Rødsrud of the Museum of Cultural History.

Musicians recorded by the Hitsville and Athletic Sound studios in the Halden region include Motorpsycho, Madrugada, Morten Harket, and Kurt Nilsen.

Artists born in Halden that are represented in the Norwegian National Gallery in Oslo include Thomas Fearnley (1802–1842) and Jacob Mathias Calmeyer (1802–1883).

Other significant artists that lived in Halden, but were not born there, include Johannes Fintoe (1786–1870) and Heinrich August Grosch (1763–1843).

Grosch's son, Christian Heinrich Grosch (1801–1865), who moved with his parents to Halden at the age of ten, became an influential architect, whose works include seventy-eight churches (including Immanuel Church in Halden), the Bank of Norway, the Oslo Stock Exchange, and the original university buildings in Oslo.

Current archaeological excavations includes Jellestadskipet (Gjellestadskipet) located a stone's throw from Jellhaugen; it was first photographed in 2018.

The two handball clubs, Tistedalens TIF in the first division and HK Halden, have teams for children, youth and adults.

It is in fact to create an environment “as unprisonlike as possible.” This reflects the flagship of the Norwegian justice system, which focuses on rehabilitation rather than punishment.