The species Homostichanthus duerdeni and Anemonia sargassensis are recorded for the first time in the Mexican Caribbean. Homostichanthus duerdeni is taxonomically diagnosed, and images from living specimens, including external and internal features and cnidae, are provided. The extension of the geographical distribution range of A. sargassensis is discussed, as well as the taxonomic status of the previous records of actiniarians in the Mexican Caribbean. An updated list of sea anemones in the region is provided, comprising 15 species in 11 localities along the Mexican Caribbean.