Gustav Riehl (10 February 1855, in Wiener Neustadt – 7 January 1943, in Vienna) was an Austrian dermatologist.
From 1872 he studied medicine at the University of Vienna, where he later worked as an assistant in the clinic of skin diseases and syphilis under Ferdinand Ritter von Hebra and Moritz Kaposi. In 1896 he became an associate professor of dermatology and syphilology at the University of Leipzig, attaining a full professorship in 1901. In 1902 he returned to the University of Vienna, where in 1921/22 he served as academic rector.[1]
He made contributions in his work involving skin tuberculosis, severe burn therapy, leishmaniasis, mycosis fungoides, radiation therapy, et al.[1] In 1886, with Richard Paltauf, he described tuberculosis verrucosa cutis,[2] and in 1917 described a type of hyperpigmentation known today as Riehl melanosis.[3][4] At Vienna General Hospital he established a radiation treatment ward.[5]