Eidfjord is a municipality in Vestland county, Norway. The municipality is located in the traditional district of Hardanger. The administrative centre of the municipality is the village of Eidfjord, where the majority of the municipal population lives. The other major population centre in the municipality is the village of Øvre Eidfjord.

Eidfjord is situated at the end of the Eid Fjord, an inner branch of the large Hardangerfjorden. The village of Eidfjord is a major cruise ship port of call. Eidfjord has several tourist sites, like the Sima Power Plant which is built into the mountain itself, the Måbødalen valley, and the Vøringsfossen waterfall which has a free fall of 182 metres (597 ft). Large parts of the Hardangervidda (Europe's largest mountain plateau) are located in Eidfjord. The Hardangervidda Natursenter, a visitors centre and museum for Hardangervidda National Park, is located in Øvre Eidfjord.

The 1,491.5-square-kilometre (575.9 sq mi) municipality is the 59th largest by area out of the 356 municipalities in Norway. Eidfjord is the 341st most populous municipality in Norway with a population of 906. The municipality's population density is 0.7 inhabitants per square kilometre (1.8/sq mi) and its population has decreased by 5.4% over the previous 10-year period.

In 2016, the chief of police for Vestlandet formally suggested a reconfiguration of police districts and stations. He proposed that the police station for Ullensvang og Eidfjord be closed.