Hans Otto Friedrich Schlossberger (born 22 September 1887 in Alpirsbach, died 27 January 1960 in Stuttgart) was a German physician, who was known for his research in immunology, medical microbiology, epidemiology and antimicrobial chemotherapy, especially on syphilis, typhus, gas gangrene, diphtheria, erysipeloid of Rosenbach, tuberculosis, malaria and leptospirosis. He was one of the leading immunologists and bacteriologists of Germany during his lifetime, and was a student and collaborator of the Nobel laureates Paul Ehrlich and Emil von Behring, two of the principal founders of the field of immunology.