The Actinobacteriophage Database (PhagesDB) is a comprehensive, interactive, database-backed website that collects and shares information related to the discovery, characterization and genomics of viruses that infect Actinobacterial hosts. To date, more than 8000 bacteriophages-including over 1600 with sequenced genomes-have been entered into the database. PhagesDB plays a crucial role in organizing the discoveries of phage biologists around the world-including students in the SEA-PHAGES program-and has been cited in over 50 peer-reviewed articles. Availability and Implementation: http://phagesdb.org/. Contact: [email protected].