Sugar Loaf Bay is a bay in the Upernavik Archipelago in the Qaasuitsup municipality in northwestern Greenland. It is an indentiation of northeastern Baffin Bay. The name of the bay derives from the name of an island of the same name in the bay, Sugar Loaf Island (Greenlandic: Uummannaq, not to be confused with Uummannaq Island).
The bay is located in the northern part of Upernavik Archipelago, between Qullikorsuit Island in the south and Nuussuaq Peninsula in the north.
At its widest − from the Nuussuup Nuua promontory on Nuussuaq Peninsula to the Nuussua cape on Kittorsaq Island − Sugar Loaf Bay stretches for 22.5 km (14.0 mi). The length of the bay reaches its maximum of 41.3 km (25.7 mi) at the point where the Greenland ice sheet (Greenlandic: Sermersuaq) drains into the bay via Cornell Glacier.
There are several islands and skerries in the bay, scattered over the entire area of the bay. Amitsorsuaq Island is the largest island in the bay, forming its southern boundary, and together with Nasaussaq Island separating the bay from the Nasaussap Saqqaa fjord.
Ikermiorsuaq Island occupies the center of the bay, while in the northern part of the bay there is a chain of islands paralleling the coastline of Nuussuaq Peninsula. These are, from northeast to southwest: the small Inussulikassak, Paornarqortut, Itissaalik (the largest of the chain), Saarlia, Timilersua (the second-largest), and Sugar Loaf Island.