Ranunculus aydogdui sp. nov. is described from Tuz Golu (Salt Lake), Aksaray, Turkey. It is compared to three similar species, R. flammula, R. pulchellus var. pulchellus and R. indivisus and it is found that R. aydogdui is distinguished from them e.g. by having tuber roots. A comprehensive description, ecology, distribution map, detailed photographs, pollen morphology and comparison of the new species with closely related species are provided. The new species is assessed as Critically Endangered (CR) following IUCN Red List Categories and Criteria.