Two genera of marine red algae, Rhodogorgon and Renouxia, are reported from Thai waters. Rhodogorgon ramosissima was collected from the east coast of the Gulf of Thailand (the Pacific Ocean) and Renouxia antillana from the Andaman Sea (the Indian Ocean). The two genera differ from other calcified red algae as they possess calciferous cells surrounded by calcite husks. The present study indicates that Rhodogogon ramosissima and Renouxia antillana occur in Thailand and provide additional records of the distribution of the gorgonian-like marine red algae in the southeast Asian countries and the Pacific Ocean.