Major General Sir Thomas Owen Marden KBE, CB, CMG (15 September 1866 – 11 September 1951) was a British Army officer, active during the Boer War and the First World War, where he commanded a battalion of the Welch Regiment, a brigade, and finally 6th Division. Following the war, he commanded a British occupying force in Turkey during the Chanak Crisis in the early 1920s.