Moss Jernverk ("Moss Ironworks") was an ironwork in Moss, Norway. Established in 1704, it was for many years the largest workplace in the city, and melted ore, chiefly from Arendalsfeltet (a geologic province in Norway). With power from the nearby waterfalls it manufactured many different products. From around the middle of the 1700 century the works were the leading armory in the country and produced hundreds of heavy iron cannons. The first rolling mill in Norway was also located here.