David Howard Sachs, born January 10, 1942, is an American immunologist. He is widely recognized for his discovery of MHC class II and for his seminal studies in the fields of transplant immune tolerance and xenotransplantation. Sachs pursued his education at Harvard College, graduating summa cum laude in organic chemistry in 1963, and then completed a master's degree equivalent at the University of Paris on a Fulbright Fellowship in 1964.