Sefton Glacier (80°45′S156°52′E / 80.750°S 156.867°E / -80.750; 156.867) is a glacier about 10 nautical miles (18km) long, flowing into the south side of Byrd Glacier just west of Rundle Peaks. Named by the Advisory Committee on Antarctic Names (US-ACAN) for Ronald Sefton, ionospheric physicist, a member of the Byrd Station winter parties of 1962 and 1964.