Lepismatid silverfish found on Norfolk Island, Lord Howe Island, Balls Pyramid and the Herald Cays are examined. Despite their isolated locations and small land area, these islands each support one or two species of the genus Heterolepisma Escherich. A phylogenetic analysis based on 23 morphological characters conducted using 14 adequately described Heterolepismatinae revealed deep rooted phylogenetic divergences and a new genus Maritisma is erected for M. coralinium sp. nov.; Heterolepisma dispar Uchida from Japan is transferred to the new genus. Heterolepisma howense Womersley is redescribed from the type material and additional specimens from Lord Howe Island; it is also the only species of Heterolepisma so far found on Norfolk Island. Heterolepisma milledgei sp. nov. is described from both Lord Howe Island (including Blackburn Island in its lagoon) and Balls Pyramid. Heterolepisma pyramidum sp. nov. is described from Balls Pyramid. Maritisma coralinium gen. nov., sp. nov. and H. heraldense sp. nov. are described from the Herald Cays; both are considered as endangered by rising sea level however H. heraldense sp. nov. may be conspecific with the inadequately described H. rouxi Silvestri from New Caledonia. Limited molecular data (COI and 28S) were obtained for two of the Lord Howe Island/Balls Pyramid species.