Franz Steindachner (11 November 1834 in Vienna – 10 December 1919 in Vienna) was an Austrian zoologist, ichthyologist, and herpetologist. He published over 200 papers on fishes and over 50 papers on reptiles and amphibians Steindachner described hundreds of new species of fish and dozens of new amphibians and reptiles. At least seven species of reptile have been named after him.
Being interested in natural history, Steindachner took up the study of fossil fishes on the recommendation of his friend Eduard Suess (1831-1914). In 1860 he was appointed to the position of director of the fish collection at the Naturhistorisches Museum, a position which had remained vacant since the death of Johann Jakob Heckel (1790-1857).
Steindachner's reputation as an ichthyologist grew, and in 1868 he was invited by Louis Agassiz (1807-1873) to accept a position at the Museum of Comparative Zoology at Harvard University. Steindachner took part in the Hassler Expedition of 1871–1872 (a journey that circumnavigated South America from Boston to San Francisco). In 1874 he returned to Vienna, and in 1887 was appointed director of the zoological department of the Naturhistorisches Museum. In 1898 he was promoted to director of the museum.
He traveled extensively during his career, his research trips taking him throughout the Iberian Peninsula, the Red Sea, the Canary Islands, Senegal, Latin America, etc. In his zoological studies, his interests were mainly from a systematic and faunistic standpoint.
Among his better known works in ichthyology are Ichthyologische Notizen (1863, published over 8 editions), Ichthyologische Beiträge (1874), and Beiträge zur Kenntniss der Flussfische Sudamerikas (1879), the latter work dealing with river fish of South America. In the field of herpetology, he published Die schlangen und eidechsen der Galapagos-inseln (Snakes and lizards of the Galapagos Islands, 1875).
From 1875, he was member of the Vienna Academy of Sciences. In 1892 he became a member of the German Academy of Sciences Leopoldina.