Major-General Sir David Bruce KCB FRS FRCP FRSE (29 May 1855 – 27 November 1931) was an Australian-born British pathologist and microbiologist who investigated Malta fever (later called brucellosis in his honour) and African trypanosomiasis (sleeping sickness in humans and nagana in animals). He discovered a protozoan parasite transmitted by insects, later named Trypanosoma brucei after him. Working in the Army Medical Service and the Royal Army Medical Corps, his major scientific collaborator was his microbiologist wife Mary Elizabeth Bruce (née Steele), with whom he published more than thirty technical papers.