Tasiilaq is a town situated on Ammassalik Island in southeastern Greenland, within the municipality of Sermersooq. It lies on the shore of a natural harbour in Tasiilaq Fjord, which is an inlet of the larger Ammassalik Fjord emptying into the North Atlantic. The settlement is located approximately 106 kilometers south of the Arctic Circle, positioned near the Sermilik Fjord to the west.