The Daijō-daijin or Dajō-daijin (太政大臣, Chancellor of the Realm) was a government position in Japan in the late Nara and Heian periods.
The position was established in the Taihō Code of 702. The official acted in the context of a Council of State (daijō-kan) which was made up of the three men.
- the Chancellor or Prime Minister
- the Minister of the Left (sadaijin)
- the Minister of the Right (udaijin)
The Taihō Code system was replaced in the Meiji period. For a short time, this office continued to be part of early Meiji government.