Hamar (help·info) is a town and municipality in Hedmark county, Norway. It is part of the traditional region of Hedmarken. The administrative centre of the municipality is the town of Hamar. The municipality of Hamar was separated from Vang as a town and municipality of its own in 1849. Vang was merged back into Hamar on 1 January 1992.

The town is located on the shores of lake Mjøsa, Norway's largest lake, and is the principal city of Hedmark county. It is bordered to the northwest by the municipality of Ringsaker, to the north by Åmot, to the east by Løten, and to the south by Stange.

The municipality (originally the town) is named after the old Hamar farm (Old Norse: Hamarr), since the medieval town was built on its ground. The name is identical with the word hamarr which means "rocky hill".

The coat-of-arms shows a Black Grouse sitting in the top of a pine tree on a white background. It was first described in the anonymous Hamarkrøniken (The Hamar Chronicle) written in 1553.

Between 500 and 1000 AD, Aker farm was one of the most important power centres in Norway, located just a few kilometres away from today's Hamar. Three coins found in Ringerike in 1895 have been dated to the time of Harald Hardråde and are inscribed Olafr a Hamri.