The species of the genus Lordithon Thomson (Staphylinidae: Tachyporinae) of North and Central America are revised. Thirty-seven species are recognized. Sixteen new species are described: scutellaris, appalachianus and notabilis from eastern North America; difficilis and oregonus from the Pacific Northwest; fungicola transcontinental in North America; and nubicola, dubius, newtoni, howdeni, ashei, hidalgoensis, antennatus, consors, blandus, and oreophilus from Mexico. The following species names are placed in synonymy: cascadensis hatchi Malkin (= cascadensis Malkin); cincticollis Say (= thoracicus thoracicus Fabricius); occiduus Casey (= thoracicus thoracicus Fabricius); alticola Sharp (= obliquus Sharp); kelleyi Malkin (= bimaculatus Couper) and elefas Bernhauer (= longiceps LeConte). L. venustus Melsheimer is reduced to a subspecies of thoracicus Fabricius. The species festivus Sharp, obliquus Sharp, smithi Bernhauer, and mexicanus Bernhauer are transferred to Lordithon from the genus Bolitobius. Lordithon lunulatus is doubtfully recorded from North America for the first time.The usage of the generic group names Lordithon Thomson, Bolitobius Samouelle, Megacronus Stephens, Bryocharis Boisduval and Lacordaire, Carphacis des Gozis, and Bolitobus Tottenham is discussed. The genus Lordithon is divided into two subgenera, Lordithon Thomson and Bolitobus Tottenham (not Bolitobius Samouelle). The male aedeagus and other major diagnostic characters are illustrated and the distribution of each species mapped.The species rubescens Hatch, varions Hatch, fenderi Hatch and biseriatus Mannerheim are transferred from Lordithon to the genus Bryoporus Kraatz.Lectotypes are designated for the following species: niger Gravenhorst, axillaris Gravenhorst, festivus Sharp, anticus Horn, poecilus Mannerheim, facilis Casey, arizonensis Bernhauer, obliquus Sharp, alticola Sharp, smithi Bernhauer, mexicanus Bernhauer, cinctus Gravenhorst, gentilis LeConte, elefas Bernhauer and rostratus LeConte. Neotypes were designated for: angularis Sachse, trimaculatus Say, cincticollis Say, obsoletus Say and atricaudatus Say.
