Challenges in cultivating microorganisms have limited the phylogenetic diversity of currently available microbial genomes. This is being addressed by advances in sequencing throughput and computational techniques that allow for the cultivation-independent recovery of high-quality bacterial and archaeal genomes directly from metagenomic data. In this study, we recovered 7,903 uncultivated genomes from >1,000 metagenomes available from the Sequence Read Archive. These genomes increase the phylogenetic diversity of current archaeal and bacterial genome trees by >30%.