Hesperis ozcelikii A. Duran sp. nova (Brassicaceae) is described and illustrated from South Anatolia, Turkey. The species grows in landslipped places, open forest, roadsides and serpentine, pebbly slopes in Sütçüler (C3 Isparta province). It is closely related to Hesperis aspera, an endemic confined to southwest Anatolia. Diagnostic morphological characters, ecology and biogeography of H. ozcelikii are discussed. The pollen characteristics and seed coat surface of H. ozcelikii and H. aspera were examined by SEM. Hesperis ozcelikii is diploid with a new chromosome number of 2n = 12.