Dahlbreen is a glacier in Oscar II Land at Spitsbergen, Svalbard. It is named after whaler Thor Dahl. The glacier has a length of about fifteen kilometers, extending from Løvenskioldfonna to Forlandsundet. Among its tributary glaciers are Ujamnbreen, Bærumbreen and Fjelgbreen. Retreatment of the glacier has formed the bay of Dahlbrebukta.
Coordinates: 78°37′N 12°36′E / 78.62°N 12.60°E