Moritz Kaposi (Hungarian: Kaposi Mór, pronounced [ˈkɒpoʃi ˈmoːr]; 23 October 1837 in Kaposvár, Hungary – 6 March 1902 in Vienna, Austria-Hungary) was a Hungarian physician and dermatologist who discovered the skin tumor that received his name (Kaposi's sarcoma).
Born to a Jewish family, originally his surname was Kohn; but, with his conversion to the Catholic faith, he changed it to Kaposi in 1871, in reference to his town of birth. One purported reason behind this is that he wanted to marry a daughter of current dermatology chairman, Ferdinand Ritter von Hebra, and advance in the society, which he could not have done being of Jewish faith. This seems unlikely because he married Martha Hebra and converted to Catholicism several years prior to changing his name, by which time he was already well established in the Vienna University faculty and a close associate of von Hebra. A more plausible explanation is based on his own comments to colleagues that he changed his name to avoid confusion with five other similarly named physicians on the Vienna faculty. Rumors about the sincerity of both his marriage and his concerns about his Jewish ancestry may have arisen through professional jealousy (William Dubreuilh (1857–1935), first professor and chairman of dermatology in Bordeaux: "On disait de Kaposi qu´il avait pris la fille de Hebra, sa maison, sa chaire et sa clientèle, laissant le reste à son beau-frère Hans Hebra." - "It was said of Kaposi that he had taken the daughter of Hebra, his home, his chair and his clientele, leaving the rest to his brother-in-law, Hans Hebra.")
In 1855, Kaposi began to study medicine at the University of Vienna and attained a doctorate in 1861. In his dissertation, titled Dermatologie und Syphilis (1866) he made an important contribution to the field. Kaposi was appointed as professor at the University of Vienna in 1875, and in 1881 he became a member of the board of the Vienna General Hospital and director of its clinic of skin diseases.