A revision of the species, genera, and subfamilies of the amaurobiid spiders found in the Nearctic Region is presented. Over 10,600 specimens were examined. Eighty-seven species are recognized, four of which are allochthonous. Forty-one species are described as new: Amaurobius corruptus, A. diablo, A. distortus, A. galeritus, A. intermedius, A. minutus, A. palomar, A. pilosus, A. prosopidus, A. tamalpais, A. transversus, A. triangularis, A. tulare, A. vexans, Callioplus spenceri, C. wabritaskus, Callobius gertschi, C. guachama, C. hyonasus, C. klamath, C. manzanita, C. panther, C. paskenta, C. pauculus, C. paynei, C. rothi, C. sierra, C. tehama, Goeldia chinipensis, Pimus desiccatus, P. eldorado, P. iviei, P. napa, P. nawtawaketus, P. salemensis, Zanomys aquilonia, Z. feminina, Z. hesperia, Z. ochra, Z. sagittaria, Z. ultima. Eleven species names are newly synonymized. One new name, and seven new combinations are proposed.Eleven genera in five subfamilies are recognized: Amaurobius, Callioplus, Callobius, Pimus, and Zanomys in the Amaurobiinae; Arctobius in the Arctobiinae, NEW SUBFAMILY; Ixeuticus in the Desinae; Metaltella in the Metaltellinae; Goeldia, Titanoeca, and Tugana in the Titanoecinae. The generic name Walmus is newly synonymized with Amaurobius.Keys are provided for the subfamilies, genera, and for most of the species. Each genus and species is described and synonymies are listed. The distribution of most of the species is presented by locality records and distribution maps. A subfamily and generic phylogeny, and a short zoogeographic analysis are given. Ichneumonid and dipteran parasites and mermithid (Nematoda) worms in adult or subadult specimens are recorded for the first time for several species.