The Crimean Peninsula holds a large number of hypersaline water bodies. Our studies focused on these poorly investigated habitats, and included few brackish and freshwater ponds. Seventeen species were identified, of which only 4(5) were collected from hypersaline waters sometimes with extremely high salinities (Acanthocyclops sp. copepodid, 210 ppt; Eucyclops sp. copepodid, 150 ppt; Diacyclops bisetosus and Cyclops furcifer, 140–150 ppt). We also report on the occurrence of three alien thermophilic species (Eucyclops roseus Ishida, 1997, Mesocyclops isabellae Dussart et Fernando, 1988, and Mesocyclops pehpeiensis Hu, 1943) from the brackish and fresh waters of Crimea. Morphological descriptions, illustrations of the diagnostic characters and comments on relevant taxonomic issues are supplemented with discussion of the putative ways of dispersal of the alien copepods to Crimea. We provisionally reinstate Eucyclops roseus, regarded by others as a subspecies of E. agiloides (G. O. Sars, 1909), and retain the name Acanthocyclops trajani Mirabdullayev et Defaye, 2002 which was recently synonymized with A. americanus (Marsh, 1893) here considered a nomen dubium. Species accumulation curves based on our and literature data showed that significantly larger sampling efforts could yield a total of 6–8 species in the hypersaline waters and 47–50 species in all types of continental waters of Crimea.