Thomas Mountains () is a separate cluster of rocky mountains, about 5 nautical miles (9 km) long, standing 15 nautical miles (28 km) northeast of Mount Horne in Palmer Land. Discovered by the Ronne Antarctic Research Expedition (RARE), 1947–48, under Ronne, who named these mountains for noted author and radio commentator Lowell Thomas, a supporter of the expedition.
This article incorporates public domain material from the United States Geological Survey document "Thomas Mountains" (content from the Geographic Names Information System).