Beiar Fjord is a fjord in Nordland, Norway. The fjord lies mostly within Beiarn Municipality, but the westernmost part of the fjord lies in Gildeskål Municipality. It has a length of about 20 kilometers (12 mi). The Norwegian County Road 17 crosses the fjord near the mouth via the Kjellingstraumen Bridge. The fjord ranges from 80 metres (260 ft) to 2 kilometres (1.2 mi) wide throughout its course.