Ceratodon purpureus (Hedw.) Brid. is generally considered to be a weedy, ubiquitous and cosmopolitan moss species. It is very rare on Subantarctic islands in the Kerguelen Province and hitherto it was only occasionally collected on Îles Kerguelen and it is absent from Îles Crozet. The former report of this species from Marion Island in the Prince Edward Islands archipelago proved to be based on misidentifications and the voucher collections represented Dicranella gremmenii Ochyra. C. purpureus is here reported for the first time from four stations on Marion Island and the local plants are briefly characterized and illustrated.