The Hallett Peninsula () is a triangular, dome-shaped peninsula, long, with cliffs on its eastern seaboard side and on its west side. The peninsula extends from Cape Hallett to Cape Wheatstone and is joined to the mainland by a narrow ridge between Tucker Glacier and Edisto Inlet. It was so named by the New Zealand Geological Survey Antarctic Expedition (NZGSAE), 1957–58, because Hallett Station on Seabee Hook was established at the north end of the peninsula.