An account is given of the 16 species of marine triclads now known from Australia and New Zealand and their subantarctic territories. These include five here newly described, three not previously recorded from the region, and one problematic species. A key to the species is provided and descriptions of the previously known species are corrected and/or supplemented. Two new genera are established, one – Jugatovaria – for a new species and another one – Obrimoposthia – to contain the new species O. acuminata together with three former members of the genus Procerodes. Procerodes hallezi, reported by Nurse (1964) from Macquarie I., is conspecific with O. ohlini. The species Miava ernesti is transferred to the genus Synsiphonium, and Palombiella macquari is established as its junior synonym.