Ryoen (August 24, 1179 - February 26, 1220) was a priest of Kofuku-ji Temple during the late Heian period through the early Kamakura period. Ryoen's father was Kanezane KUJO, who was the Daijo-daijin (Grand minister of state). He was a disciple of Jien, who was the younger brother of Kanezane. Ryokai, who later became Tendai-zasu (head priest of the Tendai sect), was his brother.
Ryoen entered into priesthood at Kofuku-ji Temple in 1189 following his father's will, and learned Dharmalogy of the Hosso Study from his master Shinen, who had just resigned from the position of betto (chief officer). Ryoen became the koshi (priest lecturer) of Yuimae (a Buddhist service for the Yuima Sutra held at Kofuku-ji Temple) in 1196 at the age of 18. Because of his excellent talent, not only his master Shinen and his father Kanezane, but also Gaen who was the younger brother of MINAMOTO no Michichika (he was Kanezane's political enemy) had high expectations to Ryoen, and assumed the position of betto from Gaen at Kofuku-ji Temple in 1207.
However, since he was born weak and could not handle the hard work of betto, in the following year 1208, Ryoen resigned from the position in just over a year. In 1218, he became Sojo (high-ranking Buddhist priest) and assumed the position of betto from Gaen, who had taken the position again, but died in 1220 at the Ichijo-in Temple while he was still in the position.