Josef Velenovský (22 April 1858 – 7 May 1949) was a Czech botanist, mycologist, pteridologist, and bryologist. He also worked with fossils. He was a research investigator and professor in the Botanical Institute of the University of Prague, alternating with his colleague Ladislav Josef Čelakovský. He was also professor of botany at Charles University, where he concentrated in the study of mycology in final half of his life. Velenovský collected innumerable material, particularly in new central Bohemia, and described at least 2000 species of fungi. Many of his type specimens and other collections are located in the herbarium of the Národní Museum of Prague.