Anton Rzehak (26 May 1855 in Neuhof, near Nikolcitz – 31 March 1923 in Brno) was a Moravian geologist, paleontologist and prehistorian. He studied chemistry and geology at the University of Technology in Brünn, where from 1880 to 1884, he worked as an assistant to Alexander Makowsky (1833–1908). In 1883 the two men published a geological map on the environs of Brünn. The foraminifer genus Rzehakina bears his name.