Minister of the Right[1] (右大臣, Udaijin) was a government position in Japan during the Asuka to Meiji era.

The Asuka Kiyomihara Code of 689 marks the initial appearance of the Udaijin in the context of a central administrative body called the Daijō-kan (Council of State).

This early Daijō-kan was composed of the three ministers—the Daijō-daijin (Chancellor), the Sadaijin (Minister of the Left) and the Udaijin.

This was the first time since Minamoto no Sanetomo in 1218 that a member of the warrior class had been appointed Udaijin.

The warrior class was able to use the high imperial court positions of Daijō-daijin, Sadaijin, and Udaijin, which had originally belonged to the nobility, as a means of establishing their own authority.