Shackleton Glacier is a major Antarctic glacier, over 60 nautical miles long and from 5 to 10 nautical miles wide, descending from the Antarctic Plateau from the vicinity of Roberts Massif and flowing north through the Queen Maud Mountains to enter the Ross Ice Shelf between Mount Speed and Waldron Spurs. Discovered by the United States Antarctic Service (USAS) (1939–41) and named by the Advisory Committee on Antarctic Names (US-ACAN) for Sir Ernest Shackleton, British Antarctic explorer.