Selenococcidium is a genus of parasitic protozoa in the phylum Apicomplexa. There is one recognised species in this genus - Selenococcidium intermedium. This species infects the intestinal tract of European lobsters (Homarus gammarus). The genus and species were described by Léger & Duboscq in 1909 The specific name is derived from the appearance of the trophozoites which possesses aspects of both the coccidia and gregarines.