Thomas Glacier () is a roughly Z-shaped glacier which drains the southeast slopes of Vinson Massif and flows for 17 nautical miles (31 km) through the south part of the Sentinel Range, Ellsworth Mountains, leaving the range south of Johnson Spur. Discovered by U.S. Navy Squadron VX-6 on photographic flights of December 14–15, 1959, and mapped by United States Geological Survey (USGS) from the photos. Named by Advisory Committee on Antarctic Names (US-ACAN) for R. Admiral Charles W. Thomas, USCG, veteran of Antarctic expeditions in the 1950s.
This article incorporates public domain material from the United States Geological Survey document "Thomas Glacier" (content from the Geographic Names Information System).