Thomas Mountain, Thomas Mountains, or Mount Thomas, may refer to;

• Thomas Mountain (California), a peak in the San Jacinto Mountains, Riverside County, California
  • Little Thomas Mountain, a secondary peak in the San Jacinto Mountains, Riverside County, California
• Thomas Mountain, California, an unincorporated community in Riverside County
• Thomas Mountain Summit, a peak in Fairfield County, Connecticut
• Thomas Mountains, a mountain range in Palmer Land, Antarctica

• Mount Thomas, a fictional town in Australian television drama Blue Heelers
• Mount Thomas (Alaska), a mountain in the Chugach Mountains, Alaska
• Mount Thomas (Antarctica), a mountain in the Prince Charles Mountains

• Thomas Mountain, winner of the 1978 Charles Ives Prize