Eidfjord municipality sits at the innermost part of the Hardangerfjorden and it stretches inland to include part of the vast Hardangervidda plateau. Part of the Hardangervidda National Park lies in the municipality. Eidfjord municipality borders Ullensvang Municipality to the southwest, the municipalities of Nore og Uvdal and Hol (both in Viken county) to the east, and Ulvik Municipality to the north.