Nilus of Constantinople was a 14th-century Hesychast who served as the Ecumenical Patriarch of Constantinople from 1380 until his death in 1388. Born in the Byzantine Empire around 1350, he held a significant leadership role within the Orthodox Church during a complex period of history. His tenure included important administrative decisions, such as the 1380 synod that appointed the Bulgarian-born Hesychast Cyprian as the metropolitan of Moscow.