Mount Ptolemy (68°33'S 65°58'W) is an isolated block mountain with four main summits, the highest rising to 1,370 meters. It lies close north of the Traffic Circle on the northwestern side of Mercator Ice Piedmont, Antarctic Peninsula. First observed by Finn Ronne and Carl Eklund of the U.S. Antarctic Service, 1939–41, from their sledge route through the Traffic Circle.