Six genera and 13 species of red algae, characteristic of sand-plain habitats between 10 and 28 m depths, are reported for the first time for the Caribbean coast of Colombia. They are Amphiroa beauvoisii Lamouroux, Halymenia pseudofloresia Collins et Howe, Dudresnaya bermudensis Setchell, D. crassa Howe, Sebdenia flabellata (J. Agardh) Parkinson, Agardhiella subulata (C. Agardh) Kraft et Wynne, Sarcodiotheca dichotoma (Howe) Dawson, S. divaricata W. R. Taylor, Chrysymenia enteromorpha (Harvey) Farlow, Lomentaria corallicola Børgesen, Dictyurus occidentalis J. Agardh, Laurencia brongniartii J. Agardh, and Micropeuce mucronata (Harvey) Kylin ex E. C. Oliveira. Agardhiella subulata differs from Solieria filiformis (Kützing) Gabrielson both in morphology and in habitat. Sarcodiotheca caribaea from the Caribbean Sea is considered to be conspecific with S. dichotoma from the Gulf of California (Mexico), and it is reported for the second time for the Atlantic Ocean. Sarcodiotheca divaricata is reported for the second time for the Atlantic Ocean and for the first time for the Caribbean Sea. Lomentaria rawitscheri Joly (1957) from Brazil is considered here to be conspecific with L. corallicola Børgesen (1939) from the Gulf of Iran.