Hammerfest (; ) is a municipality in Troms og Finnmark county, Norway. (From 2024, it will be in Finnmark county.) The administrative center of the municipality is the town of Hammerfest. The municipality has an area of and a population of 11,274 people. The population density is low, with only 4.4 people per square kilometer (1.7/m²). The municipality is made up of three large islands and several small islands. Most of it is not connected to the mainland by road.
Hammerfest was formed as a municipality in 1838. In 1992, it merged with the neighboring municipality of Sørøysund to form a larger municipality with the same name. In 2020, it became part of the newly formed Troms og Finnmark county.