Williamson Ridge () is a low snow-covered ridge, 10 nautical miles (18 km) long and 2 to 5 nautical miles (9 km) wide, that forms a western extension of Toney Mountain in Marie Byrd Land. It was mapped by United States Geological Survey (USGS) from ground surveys and U.S. Navy air photos, 1959-71. Named by Advisory Committee on Antarctic Names (US-ACAN) for Paul R. Williamson, ionospheric physicist at Byrd Station in two austral summers, 1967-68 and 1969-70.