Vice-Admiral Sir Thomas Dundas KCB (c. 1765 – 29 March 1841) was an officer of the Royal Navy, who saw service during the American War of Independence, and the French Revolutionary and Napoleonic Wars. An effective frigate captain he made a number of small captures, but did not see action in any major fleet clashes, until he was present at the Battle of Trafalgar in 1805. He played an important role in relaying signals before the battle, and in towing dismasted British ships to safety afterwards. He had a largely uneventful career thereafter, rising through the ranks and eventually dying a vice-admiral.