Billefjorden is the central fjord of the three branching from the innermost part of the Isfjorden to the northeast, in Svalbard, Norway. It is 30 km long and 5–8 km wide. Billefjorden lies between Dickson Land to the northwest and Bünsow Land in the southeast. Located on its northwestern shore is the former Russian coal mining community of Pyramiden (abandoned in 1998). To the northeast is Nordenskiöldbreen (Nordenskiöld Glacier). At its northeastern extreme is Adolf Bay.