Innaarsuit Island is located in the outer belt of islands in Tasiusaq Bay, in the south-central part of Upernavik Archipelago. In the north, it is separated from sibling Ateqanngitsorsuaq Island by a very narrow channel. The island is hilly, but not mountainous, with Saattup Akia mountain the highest point on the island, at . The inner waterways of Tasiusaq Bay separate it from the small Naajaat Island in the east, and from Qaarsorsuatsiaq Island in the west. Several skerries buffer the southern coast of the island.