A new genus of holothuroid, Calcamariina O Loughlin, and five new species of holothuroids, with authors O Loughlin & Skarbnik-López, from near Heard and McDonald Islands on the Kerguelen Plateau in the Southern Ocean are described: Calcamariina hibberdi, Calcamariina moorea, Echinocucumis ampla, Psolus heardi, Paracaudina championi. The new species Paracaudina championi has the diagnostic characters of both Paracaudina Heding and Hedingia Deichmann. Molpadia violacea Studer is raised out of synonymy with Molpadia musculus Risso. Molpadia violacea is reviewed, and an extended distribution around Antarctica is proposed. The distribution of Molpadia magdae O Loughlin (in O Loughlin et al.) is extended from the South Shetland Islands to Prydz Bay. Pseudopsolus macquariensis forma gruai Cherbonnier & Guille is raised to species status. Laevocnus O Loughlin (in O Loughlin et al.) is an objective junior synonym of Pentactella Verrill. A sensu stricto diagnosis is provided for Pentactella. The always smaller, brood-protecting Psolus ephippifer Thomson specimens may be juveniles of the sympatric and always larger, non-brooding, Psolus paradubiosus Carriol & Féral specimens. Comprehensive lists are provided for all holothuroids that have been reported from the vicinity of Heard and McDonald Islands, and for the Kerguelen Plateau. Individual lists are provided for all holothuroid specimens from the vicinity of Heard and McDonald Islands that are held in Museum Victoria, the South Australian Museum, and the Tasmanian Museum and Art Gallery. Holothuroid species variably common to the Kerguelen Plateau, coast of Antarctica, Macquarie Island, Magellanic Region and Bouvetoya Island are listed.