Disko Bay (Greenlandic: Qeqertarsuup tunua; Danish: Diskobugten) is a bay on the western coast of Greenland. The bay constitutes a wide southeastern inlet of Baffin Bay.To the south the coastline is complicated with multiple waterways of skerries and small islands in the Aasiaat archipelago. Qasigiannguit and Ilimanaq are the main settlements in the southeastern inlet, just south of the outflow of Ilulissat Icefjord.
From the north the bay is bounded by Qeqertarsuaq, the largest island on the western coast. North of Ilulissat and west of Aluttoq Island the bay transforms into Sullorsuaq Strait separating Qeqertarsuaq from Nuussuaq Peninsula.