Two collections of fossil penguins have been made from Seymour Island, off the north-eastern end of the Antarctic Peninsula, one by a Swedish expedition in 1901-1903 and the other by a British expedition in 1946. The age has usually been considered early Miocene but is probably earlier, late Eocene now seeming most likely but still uncertain. Wiman in 1905 based six then new generic and specific names on the Swedish collection. Anthropornis nordenskjoeldii and Delphinornis larsenii are considered valid. Pachypteryx grandis is a valid species but is transferred to Anthropornis. Eosphaeniscus gunnari is a valid species transferred to Palaeeudyptes, a genus otherwise known from New Zealand and Australia. Orthopteryx gigas and Ichtyopteryx gracilis are considered essentially indeterminate, as are two groups of bones not named by Wiman. Marples named genus and species Notodyptes wimani from the British collection. The species is accepted but transferred to the New Zealand genus Archaeospheniscus. Wimanornis seymourensis, new genus and species, is based on a British specimen. This penguin fauna is essentially similar to the early (late Eocene and early Oligocene) faunas known from New Zealand. In the probable absence of species in common, geographic proximity is not indicated. The ecological similarity and some indirect evidence suggest that despite the presence of relative gigantism these penguins lived in considerably warmer waters than those of the present Antarctic coast.