Pseudoalteromonas, with a ubiquitous distribution, is one of the most abundant marine bacterial genera. It is especially abundant in the deep sea and polar seas, where it has been found to have a broad metabolic capacity and unique co-existence strategies with other organisms. However, only a fewPseudoalteromonasphages have so far been isolated and investigated and their genomic diversity and distribution patterns are still unclear. Here, the genomes, taxonomic features and distribution patterns ofPseudoalteromonasphages are systematically analyzed, based on the microbial and viral genomes and metagenome datasets. A total of 143 complete or nearly completePseudoalteromonas-associated phage genomes (PSAPGs) were identified, including 34Pseudoalteromonasphage isolates, 24 proviruses, and 85Pseudoalteromonas-associated uncultured viral genomes (UViGs); these were assigned to 47 viral clusters at the genus level. Many integrated proviruses (n= 24) and filamentous phages were detected (n= 32), suggesting the prevalence of viral lysogenic life cycle inPseudoalteromonas. PSAPGs encoded 66 types of 249 potential auxiliary metabolic genes (AMGs) relating to peptidases and nucleotide metabolism. They may also participate in marine biogeochemical cycles through the manipulation of the metabolism of their hosts, especially in the phosphorus and sulfur cycles. Siphoviral and filamentous PSAPGs were the predominant viral lineages found in polar areas, while some myoviral and siphoviral PSAPGs encoding transposase were more abundant in the deep sea. This study has expanded our understanding of the taxonomy, phylogenetic and ecological scope of marinePseudoalteromonasphages and deepens our knowledge of viral impacts onPseudoalteromonas. It will provide a baseline for the study of interactions between phages andPseudoalteromonasin the ocean.Supplementary InformationThe online version contains supplementary material available at 10.1007/s42995-022-00160-z.