Skjerstadfjorden is a fjord in the municipalities of Bodø, Fauske, and Saltdal in Nordland county, Norway. It is a 40-kilometre (25 mi) long arm off of the main Saltfjorden. It is connected to the Saltfjorden by the narrow Saltstraumen strait which has very strong tidal currents. Some of the larger villages around the fjord include Valnesfjord, Fauske, and Rognan. European route E06 runs along the eastern shore of the fjord, and the Nordlandsbanen railway line follows the eastern and northern shores of the fjord.