A new species of skink in the genus Epibator is described from Île Walpole, a small, isolated, raised vegetated limestone platform, ∼200 km ESE of southern New Caledonia. The new species is distinguished from its congeners Epibator nigrofasciolatus and E. greeri primarily by its coloration and pattern (both species), differences in scalation (greeri), and substantial genetic differentiation (nigrofasciolatus). The new species is the only extant endemic terrestrial vertebrate on Walpole. The island is small (<1.7 km2), and has a long history of past human occupation (over the last 2,500 years, including European-era exploitation for guano), resulting in degradation of the vegetation cover and introduction of invasive animal species, most significantly ants (Little Fire Ant, Yellow Crazy Ant) and rats (Pacific Rat). The species’ very limited distribution in combination with the threats posed by invasive species place it at a level of risk sufficient to be considered as Critically Endangered under IUCN Red List criteria.