The Australopacific Saprininae, containing twelve genera and forty species, are reviewed, illustrated and keyed to genera and species. Two new genera,Australopachylopusgen. n.(New Zealand, type speciesSaprinus lepidulusBroun, 1881) andIridoprinusgen. n.(Australia, type speciesI. myrmecophilussp. n.) and four new species: Saprinus (Saprinus) rarussp. n.(Australia), Saprinus (Saprinus) chathamensissp. n.(Chatham Islands, New Zealand), Saprinus (Saprinus) pseudodetritussp. n.(Chatham Islands, New Zealand) and Saprinus (Saprinus) pacificussp. n.(Kiribati) are described. The Saprininae fauna of the Australopacific Region is a mixture of northern invaders that most likely arrived to the region in early Cenozoic by ‘island hopping’ from north (Hypocaccus,Hypocacculus, severalSaprinus) and truly autochthonous taxa either with uncertain phylogenetic affinities (Iridoprinusgen. n.,SaprinodesLewis, 1891,ReichardtiaWenzel, 1944,Australopachylopusgen. n.), primitive Australopacific endemics (e.g.TomogeniusMarseul, 1862) or presumed relicts (several species ofSaprinusErichson, 1834). Several Saprininae taxa (Chalcionellus aeneovirens(Schmidt, 1890); (Gnathoncus rotundatus(Kugelann, 1792);G. communis(Marseul, 1862); Euspilotus (Neosaprinus) rubriculus (Marseul, 1855); Hypocaccus (Nessus) interpunctatus interpunctatus (Schmidt, 1885); Saprinus (S.) chalcites (Illiger, 1807) and Saprinus (S.) cupreus Erichson, 1834)) were introduced into the region with human activity. We report the first cases of myrmecophily (Iridoprinus myrmecophilusgen. et sp. n.) and termitophily (Saprinus rarussp. n.) in the Saprininae from the Australopacific Region. Lectotypes and paralectotypes of the following taxa are designated herein:Saprinus amethystinusLewis, 1900,Saprinus apricariusErichson, 1834,Saprinus artensisMarseul, 1862,Saprinus auricollisMarseul, 1855,Saprinus australasiaeBlackburn, 1903,Saprinus bistrigifronsMarseul, 1855,Saprinus certusLewis, 1888,Saprinus communisMarseul, 1862,Saprinus cupreusErichson, 1834,Saprinus cyanellusMarseul, 1855,Hister cyaneusFabricius, 1775,Saprinus dentipesMarseul, 1855,Saprinus desbordesiAuzat, 1916,Saprinus gayndahensisMacLeay, 1871,Saprinus hylaMarseul, 1864,Saprinus incisisternusMarseul, 1862,Saprinus incisusErichson, 1842,Saprinus irinusMarseul, 1862,Saprinus laetusErichson, 1834,Saprinus lepidulusBroun, 1881,Saprinus mastersiiMacLeay, 1871,Saprinus nitiduloidesFairmaire, 1883,Saprinus pedatorSharp, 1876,Saprinus pseudocyaneusWhite, 1846,Saprinus rubriculusMarseul, 1855,Saprinus sinaeMarseul, 1862,Saprinus tasmanicusMarseul, 1855,Saprinus tyrrhenusBlackburn, 1903,Saprinus variansSchmidt, 1890,Saprinus vernulusBlackburn, 1903,Saprinus viridanusLewis, 1899,Saprinus viridipennisLewis, 1901, andSaprinus westraliensisBlackburn, 1903. The synonymy ofSaprinus tyrrhenusBlackburn, 1903 is revoked and the species is considered as valid (stat. n.). Seven new synonymies are proposed:Saprinus gayndahensisMacLeay, 1871 =Saprinus laetusErichson, 1834syn. n.,Saprinus pseudocyaneusWhite, 1846 =Saprinus laetusErichson, 1834syn. n.,Saprinus mastersiiMacLeay, 1871 =Saprinus laetusErichson, 1834syn. n.,Saprinus dentipesMarseul, 1855 = Hypocaccus (Baeckmanniolus) gaudens (J.L. LeConte, 1851)syn. n., Hypocaccus (Hypocaccus) vernulus (Blackburn, 1903) = Hypocaccus (Hypocaccus) sinae (Marseul, 1862)syn. n., Saprinus (Saprinus) lindrothi Dahlgren, 1968 = Saprinus (Saprinus) prasinus Erichson, 1834syn. n., and Saprinus (Saprinus) certus Lewis, 1888 = Saprinus (Saprinus) frontistrius Marseul, 1855syn. n.The following new records are: Euspilotus (Neosaprinus) rubriculus (Marseul, 1855) (=Saprinus gnathoncoidesBickhardt, 1909) (Australia), Saprinus (Saprinus) laetus Erichson, 1834 (Lord Howe Island) and Saprinus (Saprinus) cyaneus cyaneus (Fabricius, 1775) (Lord Howe Island and Fiji).
