Culture-independent techniques such as metagenomics and single-cell genomics allow us to explore microbial diversity on the genome scale. This wealth of genomic data provides the opportunity to develop a comprehensive taxonomy based on evolutionary relationships. Here we propose a standardized archaeal taxonomy based on a concatenated protein phylogeny that conservatively removes polyphyletic groups and normalizes ranks based on relative evolutionary divergence. The robustness of the phylogeny was verified by inferring genome trees from concatenated marker gene sets using FastTree, IQ-TREE, and ExaML, and through comparisons to single-gene trees. Taxonomic curation followed the rules of the International Code of Nomenclature of Prokaryotes and recent proposals to use genome sequences as type material. From 1811 archaeal genomes, 11 phyla are described, including 3 phyla from major normalized monophyletic units from the Euryarchaeota, and a phylum resulting from the amalgamation of the TACK superphylum. The taxonomy is publicly available at the Genome Taxonomy Database (GTDB) website (http://gtdb.ecogenomic.org).