King of Ryūkyū (琉球国王, Ryūkyū koku-ō), also known as King of Lew Chew, King of Chūzan (中山王, Chūzan-ō), or more officially Ryūkyū Kingdom's King of Chūzan (琉球国中山王, Ryūkyū-koku Chūzan-ō), was the title held by several lineages in Okinawa Island from 1372 until the monarchy's dissolution in 1879.
According to the traditional official Okinawan narrative, the legendary ruler Shunten, who supposedly ascended to the throne in 1187, was first to hold the title. Additionally, the notion of a single-line of succession has been maintained despite the Crown clearly recognising several unrelated lineages acceding. However, the monarchy effectively started in 1372 when Satto greeted a Chinese envoy from the newly established Ming dynasty, although his son Bunei was the first to be officially recognized as the King of Chūzan.