Otto Hirschfeld (March 16, 1843 – March 27, 1922) was a German epigraphist and professor of ancient history who was a native of Königsberg.
In 1863 received his doctorate from the University of Königsberg, and in 1869 became a professor at the University of Göttingen. In 1872 he became a professor of classical studies at the University of Prague, and in 1876 a professor of epigraphy and ancient history at the University of Vienna. In 1885 he succeeded Theodor Mommsen (1817-1903) as professor of ancient history at the University of Berlin, where he remained until his retirement in 1917.
At Vienna he organized the Archeologic-Epigraphic Seminary with archaeologist Alexander Conze (1831-1914). Hirschfeld edited several volumes of the Corpus Inscriptionum Latinarum, in which he largely dealt with inscriptions of Gaul and Germania. Other writings include: Untersuchungen auf dem Gebiete der römischen Verwaltungsgeschichte (1876), Inscriptiones Galliae Narbonensis Latinae (1888) and Inscriptiones Aquitaniae et Lugdunensis (1899).