Thomas Trotter (1760–1832) was a Scottish naval physician and author who was a leading medical reformer in the Royal Navy and an ardent critic of the slave trade. Trotter was born in Melrose, Roxburghshire, and studied medicine under Alexander Monro (secundus) in Edinburgh.
Born in Roxburghshire in or about 1760, he studied medicine in Edinburgh. As surgeon's mate, he served on HMS Berwick in the Channel fleet in 1779, in the battle of the Doggerbank in 1781, and (apparently) at the relief of Gibraltar in 1782. He was then promoted to be surgeon; but as the reduction of the navy after the peace held out little prospect of employment, he engaged himself as surgeon on board a Liverpool Guineaman (slaver), and had medical charge of a cargo of slaves across to the West Indies. An outbreak of scurvy on board fixed his attention on the disease.
Trotter pursued medical studies in Edinburgh, and graduated M.D. in 1788. During the Spanish armament of 1790, he was appointed by Vice-admiral Robert Roddam, to be surgeon of his flagship HMS Royal William, and in 1793 was surgeon of HMS Vengeance for a voyage to the West Indies and back. In December he was appointed second physician to the Royal Hospital at Haslar, near Portsmouth, and in April 1794 was nominated by Lord Howe physician to the Channel fleet. In this capacity he served through the campaigns of 1794 and 1795, was present in the battle of 1 June 1794, appears to have been with Cornwallis on 16–17 June 1795, and to have joined the fleet under Lord Bridport very shortly after the action of 23 June. When going on board one of the ships to visit a wounded officer, he was accidentally ruptured, and rendered incapable of further service at sea.