Olsokbreen is a glacier in Sørkapp Land at Spitsbergen, Svalbard, in northern Norway.
It has a length of about seventeen kilometers, and debouches into the bay Stormbukta at the western shore of Spitsbergen.
Tributary glaciers to Olsokbreen are Kvithettbreen and Valettebreen, both coming from the east, from or between the mountains of Snøkrossen, Gråtinden, Kvithetta, Haitanna and Guilbaudtoppen.
[3] Records show that between 1900 and 2008 the Olsokbreen has receded by 3.5 kilometers.
Further images taken from 2012 showed that the open water at the north side of the glacier between the terminus and the peninsula had extended.