Moss is a coastal town and a municipality in Østfold county, Norway. The administrative centre of the municipality is the town of Moss. The city of Moss was established as a municipality on 1 January 1838 and City in 1720. The rural municipality of Jeløy was merged with the city on 1 July 1943. The former municipality of Rygge was merged into it on 1 January 2020. Its administrative district covers areas east of the town, such as the island of Dillingøy in the lake Vansjø.