This paper focuses on the role of Ōsaka (逢坂) in Nō (能) plays. On the whole, Ōsaka appears in 22 Nō plays, and the reference to this place name can be classified into three groups. (1) In some of the plays the name is only mentioned; (2) in others, someone passes the barrier of Ōsaka; (3) while in the rest, the barrier of Ōsaka is the stage for the story. In the first case, Ōsaka is used in a manner similar to the utamakura in waka poetry. In the second, conspicuously the word 関 (barrier/checkpoint) is often added to the place name, and the checkpoint of Ōsaka becomes a representation for the conditions of the world: if the barrier of Ōsaka is open, this serves as a hint that the world is in peace and is securely ruled by the emperor. The main characters of the plays of the third type are Semimaru (蝉丸) and Ono no Komachi (小野小町), who are represented in Nō plays as deities of the performing arts. This indicates that the barrier of Ōsaka while being a liminal space is considered as a sacred place where deities dwell.