The helminth fauna of the Northern white-breasted hedgehog Erinaceus roumanicus was studied in the Republic of Mordovia (Russia) for the first time. In total, 9 species of helminths were found in 23 studied hedgehogs: Trematoda—Isthmiophora melis, Strigea strigis (metacercaria); Cestoda—Hymenolepis erinacei; Nematoda—Aonchotheca erinacei, Physaloptera clausa, Crenosoma striatum, Physocephalus sexalatus (juvenile), Agamospirura minuta (juvenile); and Acanthocephala—Nephridiorhynchus major. Four parasite species (the trematode I. melis, nematodes P. sexalatus, A. minuta, and the acanthocephalan N. major) were found in hedgehogs for the first time in Russia. An overview of the helminth fauna of four species of Erinaceus hedgehogs inhabiting the Palearctic region is given. A total of 54 parasite species were recorded across Erinaceus europaeus, E. roumanicus, E. concolor and E. amurensis: 14 trematodes, 6 cestodes, 27 nematodes, and 7 acanthocephalans. Among all the studied species of hedgehogs, E. europaeus (35 species) and E. roumanicus (36) have the richest helminth faunas. The diversity of the parasite communities of Erinaceus spp. is due to the wide distribution and varied diet of these mammals. Most of the helminths found in hedgehogs are transmitted along trophic chains. Hedgehogs are the final hosts for 39 species of parasites. For 15 helminth species, Erinaceus spp. are paratenic hosts. The majority of the hedgehog’s helminth fauna is formed by host-specific parasites, of which there are 13 species. Most of the hedgehog’s parasites in the Palaearctic are facultative (non-specific) species that parasitize in various vertebrate species. The helminth fauna of Erinaceus hedgehogs is most studied in Russia and Belarus, where 17 species of parasites are found in each country. The comparative analysis of the helminth faunas of Erinaceus spp. from various regions showed, on the one hand, the originality of the helminth fauna of each hedgehog species and, on the other, the similarity of the helminth fauna of these insectivores from various countries of the Palaearctic. These features are caused by similar lifestyles and diet peculiarities of every hedgehog species in various regions of the Palaearctic. A total of 12 of the 54 helminth species found in hedgehogs have medical and veterinary significance as causative agents of dangerous helminthiasis.