David Samwell (October 151751 – November 231798) was a Welsh naval surgeon and poet. He is known by the pseudonym Dafydd Ddu Feddyg.
The journal of his experiences aboard Captain James Cook's ship Discovery provide a detailed account of the third and last voyages of Cook to the Pacific Ocean. Part of the journal Samwell, David. A Narrative of the Death of Captain James Cook. London, 1786. describes the death of Captain Cook at the hands of natives on the Sandwich Islands in 1779.