Kangen (854 - July 9, 925) was a priest of the Shingon sect during the mid Heian Period. While his secular surname is alleged to be either Hata clan or Tomo clan, the details of his origin are not clear. He came from Sanuki Province. He is also known as Hannya-ji Sojo (high-ranking Buddhist priest at Hannya-ji Temple).
In 872, Kangen entered the priesthood and received the religious precepts under Shinga, studied the doctrines of Sanron sect and Shingon Esoteric Buddhism under Shobo and went through Kanjo (the ceremony to be the successor) in 895. In 900, he became betto (the head priest) of Ninna-ji Temple. After successively holding the positions of betto of Kawara-dera Temple, Gon no Risshi (generally in Shingon sect, 15th-ranking Buddhist priest, literally, "supernumerary master of discipline"), To-ji choja (the chief abbot of To-ji Temple), zasu (a head priest) of Daigo-ji Temple, and kengyo (temple administrator) of Kongobu-ji Temple, Kangen was appointed in 923 as Gon no Sojo (the provisional lower priest in the highest position). In the meantime, Kangen founded Hannya-ji Temple, petitioned the emperor to award Kukai the title of Kobo Daishi. In addition, Kangen restructured Shingon sect, based in To-ji Temple, by storing in the Kyozo (sutra repository) the 'Sanjujo Sasshi' (30 volumes of esoteric Buddhist scripture hand-copied by priest Kukai when he was staying in China) brought back by Kukai from Tang Dynasty, and determining that the volumes should be looked after by choja of Shingon sect generations after generation.