Hamar Municipality (Norwegian: Hamar kommune; [ˈhɑ̂ːmɑr] ^ⓘ) is a municipality in Innlandet county, Norway. It is located in the traditional district of Hedmarken. The administrative centre of the municipality is the town of Hamar. Other settlements in Hamar include Hjellum, Slemsrud, Ridabu, Ingeberg, and Ilseng.

The 351-square-kilometre (136 sq mi) municipality is the 250th largest by area out of the 357 municipalities in Norway. Hamar Municipality is the 31st most populous municipality in Norway with a population of 33,441. The municipality's population density is 95.3 inhabitants per square kilometre (247/sq mi) and its population has increased by 11.4% over the previous 10-year period.

Among the municipality's responsibilities of local government, it also runs nine primary and three lower secondary schools, with a combined 3,115 pupils. The municipality also owns the power company Hamar Energi, and the sports venues Briskeby Arena, Vikingskipet, and Hamar Olympic Amphitheatre.

In 1848, the village of Hamar was granted kjøpstad status for a land area of about 400 decares (99 acres). This newly designated "town" (population: 1,025) was separated from Vang Municipality and Hamar was established as a separate municipality in 1849. On 1 January 1878, Hamar Municipality was enlarged by annexing about 800 decares (200 acres) of land and 138 people from Vang Municipality to Hamar Municipality. In 1946, a large area in Vang Municipality that surrounded the town of Hamar (population: 4,087) was transferred out of Vang Municipality and into Hamar Municipality. The next year in 1947, part of the neighboring Furnes Municipality (population: 821) was transferred into Hamar Municipality. On 1 January 1965, a part of Ringsaker Municipality (population: 100) was transferred into Hamar Municipality.

On 1 January 1992, Vang Municipality (population: 9,103) was merged with Hamar Municipality (population: 16,351) and parts of the Stensby, Hanstad, Viker, and Stammerud areas of Ringsaker Municipality (population: 224) to form a new, larger Hamar Municipality.

Historically, the municipality was part of the old Hedmark county. On 1 January 2020, the municipality became a part of the newly-formed Innlandet county (after Hedmark and Oppland counties were merged).

The municipality (originally the town) is named after the old Hamar farm (Old Norse: Hamarr). The medieval market was first built on this farm and that market eventually became a kjøpstad, the town of Hamar. This town later became a self-governing municipality. The name is identical with the word hamarr which means "stone" or "rocky hill".

The coat of arms was first granted on 2 June 1896 and re-granted on 9 July 1993. The official blazon is "Argent, a grouse sable displayed standing on a pine tree issuant from the base" (Norwegian: I sølv, en svart orrfugl med flakte vinger i toppen av et grønt furutre med naturfarget stamme). This means the arms have a field (background) has a tincture of argent which means it is commonly colored white, but if it is made out of metal, then silver is used. The charge is a black grouse sitting at the top of a pine tree. An older version of the arms had been used for a long time. The old version was first described in the anonymous Hamar Chronicle, written in 1553. Since then, it has been generally kept the same, although it has had some minor revisions over the years. The arms were designed by Andreas Bloch (1896 version) and by Per Solheim (1963 version) and Arvid Steen (1993 version). The municipal flag has the same design as the coat of arms.