Uummannaarsuk is an uninhabited island in the Sermersooq municipality in southern Greenland.

Uummannaarsuk is a 239 m high island that lies off the southeastern coast of Greenland.

It is located off Cape Cort Adelaer, to the NE of Cape Daniel Rantzau,[1] both eastern headlands of an irregularly-shaped coastal island located on the northern side of the mouth of Napasorsuaq Fjord.

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