Mysen is a Norwegian town in Indre Østfold municipality in Viken. The town has 6,729 inhabitants as of 1 January 2020, and around Mysen are the villages Hærland and Eidsberg, as well as the settlements Trømborg and Slitu. Mysen was previously its own municipality. Mysen was granted city status in 1997.


As in many other places in Eastern Norway, Mysen has grown around a railway station, after the Østfold line's Eastern line was opened in 1882. Today, the station is the terminus for most local trains on the Eastern line. Thus, Mysen has become a communication center for inner Østfold, with bus routes to most of the surrounding area, also to Töcksfors in Sweden. In 1997, the municipality decided that the place should take the city name.

From the very beginning, the economy was based on trade and small industry, and this still leaves its mark on the city. Today, it is especially the graphic industry that marks the economic life, in addition to the food and workshop industry. In Monaryggen just north of Mysen, there are large sand and gravel roofs with associated concrete industry. In the old Trollull factory, the Østfold museums have arranged a central magazine for the local museums in the county. Mysen is the seat of Heggen and Frøland District Court, and Mysen upper secondary school, formerly Indre Østfold upper secondary, is located here. Mysen also has Momarken trotting track, prison, frisbee golf park and a football team in the 3rd division (Mysen IF). For a number of years after the war, the annual Red Cross fair Momarkedet was also here. Directly above and east of the built-up area is Høytorp fort, which is now municipal open space.

The name Mysen comes from the old farm Mysen (Norse Mysin, from Mosvin). Mosi means "bog", and wine means "meadow".

The former municipality of Mysen
After first being a so-called building municipality, Mysen became an independent municipality on 1 July 1920 when it was separated from Eidsberg. On January 1, 1961, Mysen was merged again with Eidsberg. The development of the station town was largely due to Anton Hamil Mysen who was mayor in the early years of the municipality. Mysen was Norway's second smallest municipality, only Grip in Møre og Romsdal was smaller. Anton Hamil Mysen was the owner of northern Mysen and paid for the construction of Mysen church in 1903, designed by Hjalmar Welhaven.