Candidatus Parvarchaeum is a genus of Archaea in the proposed phylum of Nanoarchaeota. There are two species in the genus, Candidatus Parvarchaeum acidiphilum and Candidatus Parvarchaeum paracidiphilum (synonym Candidatus Parvarchaeum acidophilus), both of which are currently uncultured.
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI).