Sir Thomas Thomson Ewing KCMG (9 October 1856 – 15 September 1920) was an Australian politician. He began his career in the New South Wales Legislative Assembly (1885–1901) before winning election to the Division of Richmond at the inaugural 1901 federal election. He held ministerial office in the second Deakin Government as Vice-President of the Executive Council (1905–1906), Minister for Home Affairs (1906–1907), and Minister for Defence (1907–1908).