Grim Rock () is a rock awash 3 nautical miles (6 km) south-southeast of Gedges Reef and 10 nautical miles (18 km) west-northwest of Cape Perez, lying in Grandidier Channel off the west coast of Graham Land. Charted in February by the British Graham Land Expedition (BGLE) under Rymill, and so named from its appearance.
This article incorporates public domain material from the United States Geological Survey document "Grim Rock" (content from the Geographic Names Information System).