A review of the rove beetle species of the genus Gnypeta Thomson from Canada, Alaska and Greenland is presented. Eighteen species are reported from Canada of which 7 are described as new to science, 3 species described from the Palaearctic region are reported in North America for the first time: G. brincki Palm, G. carbonaria (Mannerheim), G. sellmani Brundin; 5 species, G. atrolucens Casey, G. crebrepunctata (Casey), G. groenlandica Lohse, G. nigrella (LeConte), G. uteana (Casey), represent new distribution records for Canada, and one, G. caerulea (C.R. Sahlberg), represents new province and territory records. New species are: G. ashei Klimaszewski, sp. nov.; G. dentata Klimaszewski, sp. nov.; G. lohsei Klimaszewski sp. nov.; G. minuta Klimaszewski & Webster, sp. nov., G. canadensis Klimaszewski, sp. nov., and G. saccharina Klimaszewski & Webster, sp. nov. The lectotypes are here designated for the following species from the syntype series: Gnypeta atrolucens Casey, G. baltifera (LeConte), G. bockiana Casey, G. brevicollis Casey, G. boulderensis Casey, G. brunnescens Casey, G. crebrepunctata (Casey), G. helenae Casey, G. manitobae Casey, G. nigrella (LeConte), G. oblata Casey, G. punctatula Casey, G. uteana (Casey), and G. wickhami Casey. The following new synonyms are established (first name being valid): G. uteana Casey (= G. boulderensis Casey, = G. punctatula Casey); G. crebrepunctata Casey (=G. oblata Casey), and G. laticollis Casey (=G. wickhami Casey). The species are classified into five new species groups reflecting their presumed relationships. All treated species are illustrated, and distribution maps are provided. New data on collection, habitat, and distribution are presented. A key to the identification of Canadian and Alaskan species is provided.