A catalogue of all named Nepticulidae and Opostegidae is presented, including fossil species. The catalogue is simultaneously published online in the scratchpad http://nepticuloidea.info/ and in Catalogue of Life (http://www.catalogueoflife.org/col/details/database/id/172). We provide a historical overview of taxonomic research on Nepticuloidea and a brief ‘state of the art’. A DNA barcode dataset with 3205 barcodes is made public at the same time, providing DNA barcodes of ca. 779 species, of which 2563 are identified as belonging to 444 validly published species. We recognise 862 extant and 18 fossil species of Nepticulidae in 22 extant genera and the fossil form genus Stigmellites. We count 192 valid Opostegidae species in 7 genera, without fossils. We also list seven dubious Nepticulidae names that cannot be placed due to absent type material and poor descriptions, 18 unavailable names in Nepticulidae that cannot be placed and we also list the 33 names (including four fossils) that once were placed as Nepticulidae or Opostegidae but are now excluded. All synonyms and previous combinations are listed. The generic classification follows the Molecular phylogeny that is published almost simultaneously. Subfamilies and tribes are not recognised, Trifurculinae Scoble, 1983 is synonymised with Nepticulidae Stainton, 1854 and Opostegoidinae Kozlov, 1987 is synonymised with Opostegidae Meyrick, 1893. The status of Casanovula Hoare, 2013, Etainia Beirne, 1945, Fomoria Beirne, 1945, Glaucolepis Braun, 1917, Menurella Hoare, 2013, Muhabbetana Koçak & Kemal, 2007 and Zimmermannia Hering, 1940 is changed from subgenus to full genus, whereas two genera are considered synonyms again: Manoneura Davis, 1979, a synonym of Enteucha Meyrick, 1915 and Levarchama Beirne, 1945, a synonym of Trifurcula Zeller, 1848. We propose 87 new combinations in Nepticulidae and 10 in Opostegidae, largely due to the new classification, and re-examination of some species. We propose the following 37 new synonymies for species (35 in Nepticulidae, 2 in Opostegidae):
Stigmella
acerifoliella Dovnar-Zapolski, 1969 (unavailable, = Stigmella
acerna Puplesis, 1988), Stigmella
nakamurai Kemperman & Wilkinson, 1985 (= Stigmella
palionisi Puplesis, 1984), Nepticula
amseli Skala, 1941 (unavailable = Stigmella
birgittae Gustafsson, 1985), Stigmella
cathepostis Kemperman & Wilkinson, 1985 (= Stigmella
microtheriella (Stainton, 1854)), Stigmella
populnea Kemperman & Wilkinson, 1985 (= Stigmella
nivenburgensis (Preissecker, 1942)), Nepticula
obscurella Braun, 1912 (revised synonymy, = Stigmella
myricafoliella (Busck, 1900)), Nepticula
mandingella Gustafsson, 1972 (= Stigmella
wollofella (Gustafsson, 1972)), Stigmella
rosaefoliella
pectocatena Wilkinson & Scoble, 1979 (= Stigmella
centifoliella (Zeller, 1848)), Micropteryx
pomivorella Packard, 1870 (= Stigmella
oxyacanthella (Stainton, 1854)), Stigmella
crataegivora Puplesis, 1985 (= Stigmella
micromelis Puplesis, 1985), Stigmella
scinanella Wilkinson & Scoble, 1979 (= Stigmella
purpuratella (Braun, 1917)), Stigm...