Ottokar Chiari (1 February 1853 – 12 May 1918) was an Austrian laryngologist and professor at the University of Vienna who was a native of Prague. At Vienna he was an assistant to Leopold von Schrötter (1837–1908), and later succeeded Karl Stoerk (1832–1899) as director of the laryngological clinic. He was the son of gynecologist Johann Baptist Chiari (1817–1854), and a younger brother to pathologist Hans Chiari (1851–1916). Ottokar Chiari was a specialist in the field of rhinolaryngology, and is credited for advancing new surgical procedures at the laryngological clinic in Vienna. In 1912 he introduced the transethmoid trans-sphenoid operation. In 1932, the Chiarigasse in Favoriten-Vienna was named in his honor.

Selected writings