Polychaetes represent a taxonomic group intricately connected to human society. Employed as fishing bait and frequently appearing in environmental assessments, they are also acknowledged as pests and invasive species. Comprehending the current status of Japanese species is crucial for their effective management. I present a comprehensive checklist of polychaetous annelids from Japan, which accounts for all known species up to 2024, based on more than 650 references. The number of recognized families/genera/species in Japan has increased from 64 to 77/408 to 567/1194 to 1683