This review of Cryptophagidae of Canada and the Northern United States (US) covers 142 species among the following genera: Caenoscelis (6 species), Antherophagus (4), Cryptophagus (33), Henoticus (4), Henotiderus (2), Micrambe (1), Myrmedophila (1), Pteryngium (1), Salebius (2), Telmatophilus (2), Hypocoprus (1), Atomaria (81), Curelius (1), Ephistemus (2) and Tisactia (1). All species are described morphologically and descriptions include high-definition photographs, geographic distribution data and maps as well as data on seasonal occurrence, habitats and the number of specimens examined. Some already described species that have not yet been recorded in Canada, but that have been found in bordering states with similar habitats, are also included in this publication. An interactive identification key is provided to identify all known species in Canada and Alaska together with a descriptive page for each species.