The paper considers the species composition of the fauna of several cnidarian groups of the Kara Sea. The author presents a list of species of the studied groups and indicates the types of habitat for each species. The analysis was based on the literature data, the collections of the Zoological Institute of the Russian Academy of Sciences and material collected in the Kara Sea during the expedition to the R/V Professor Multanovsky in 2019. In total, 87 species of Hydrozoa, 3 species of Scyphozoa, 4 species of Staurozoa, and 5 species of the order Alcyonacea from the class Anthozoa were recorded for the fauna of the Kara Sea, based on the new material obtained by the author and published literature data. The report presents the biogeographic structure of the discussed cnidarian groups. According to the types of biogeographic ranges, the fauna of the above-mentioned cnidarian groups in the Kara Sea mostly consists of representatives of the Boreal-Arctic type of habitat (63%), the Boreal and Amphiboreal biogeographic groups each containing 12% of the total number of described species, and the Panoceanic and Arctic groups together accounting for only 9% and 4% of the fauna of the Kara Sea. Two species new for the Kara Sea, Neoturris pileata (Forsskål, 1775) and Neoturris pileata (Forsskål, 1775), are described. Neoturris pileata is an element of the warm-water Atlantic fauna that penetrated into the Kara Sea with waters of Atlantic genesis. Nausithoe werneri is an element of the cold-water Arctic fauna that penetrated into the Novaya Zemlya Trough of the Kara Sea from the north-western side from the St. Anna Trough, which was open to the Polar Basin.