Emperor En'yū (円融天皇) (959-991) was the 64th imperial ruler of Japan. He ruled from 969 to 984. His given name was Prince Morihira (守平親王).

He was the fifth son of emperor Murakami by the empress Anshi, the daughter of Fujiwara no Morosuke , therefore the brother of the emperor Reizei.

In 967 he was elected as the crown prince, though there was his elder brother by the same mother, since his brother had no support from the Fujiwara clan.

In his reign there were a severe struggle between the Fujiwara clan over who would be appointed the Kampaku regent. He followed his mother's advice and favored Fujiwara no Kanemichi , the elder brother of his mother. He had only one son, later the emperor Ichijō by Senshi, a daughter of Fujiwara no Kaneie , another brother of his mother. He made the daughter of Kanemichi the empress, though she bore no children. Senshi and his father Kaneie got angry this elevation of their rival and were absent from the court for a long time, staying at the mansion of Kaneie with the child.

On August 27, 984 he abdicated.