David Nunes Nabarro FRCP (27 February 1874 – 3 October 1958) was a British physician who was the first bacteriologist at the Great Ormond Street Hospital for Children in London, and the hospital's first director of pathology. In 1903, he with David Bruce, Aldo Castellani and Cuthbert Christy established that sleeping sickness was caused by the blood parasite, Trypanosoma, and that it was transmitted by tsetse fly.