Genei (year of birth unknown – 840) was a priest of the Sanron sect of Buddhism who lived during the early Heian period. His place of origin is unknown.
He learned Sanron teachings from Ancho of the Daian-ji Temple, and thereafter lived in Nara Saidai-ji Temple (Nara City). In 826 he was appointed to Gon no Risshi (generally in Shingon sect, fifteenth-ranking Buddhist priest, literally, "supernumerary master of discipline") and to Risshi (the third rank of priest following Sojo and Sozu) in 827, the next year, after he lectured in the court on the doctrine of the sect at the Buddhist religious service of the memorial ceremony for the completion of Yakushi Nyorai-zo (statue of Yakushi Nyorai, the Healing Buddha). In 830 as one of the Tencho Rokupon Shusho (six books compiled at Imperial command by the six Buddhism sects during the Tencho era; each sect described the spirit and the characteristics of its own teachings) ordered by Emperor Junna, on behalf of the Sanron sect he compiled 'Daijo Sanron Daigisho' (notes of religious teachings of the Sanron sect), where he mainly developed the doctrine of his own sect, arguing down that of the Hosso sect (Japanese equivalent of the Chinese Faxiang sect) which in those days was aggressive against the Sanron sect.