Three major lineages of mites (Arachnida: Acari) are parasitic in the nasal passages of birds: Rhinonyssidae (Mesostigmata), Ereynetidae (Prostigmata), Cytoditidae, and Turbinoptidae (Astigmata). The most diverse group of avian nasal mites is the Rhinonyssidae, which are obligate endoparasites of non-ratite birds worldwide. Prior to this study, there were only four published and three unpublished records of nasal mites from birds in Canada. In Alberta, 15% of 450 birds (154 species) examined during 2003–2007 were infested with nasal mites; in Manitoba, 16% of 2447 birds (196 species) examined during 1996–2006 were infested. We have expanded the known records of host – nasal mite species in Canada from 7 to 102, a 14-fold increase. There are now 50 species of Rhinonyssidae, 7 species of Ereynetidae, and 1 species of Turbinoptidae known from birds in Alberta and Manitoba. We predict that at least 70 species of rhinonyssid mites can be found in Canada.