Nilus of Constantinople (Greek: Νεῖλος Κεραμεύς; died 1 February 1388) was Ecumenical Patriarch of Constantinople between March/April 1380 and 1 February 1388.

In 1380, he convened a synod to decide the metropolitanate of Moscow, choosing Bulgarian-born Hesychast Cyprian (1336–1406).

In 1382, Stephen of Perm wrote a letter to Nilus concerning the Strigolniki schism.

[2] Nilus was a prolific writer in the religious sphere, including many homilies and an encomium of Gregory Palamas.

[3] Nilus also wrote the Ekthesis Nea ("New Exposition"), a short treatise describing diplomatic modes of address in the Orthodox Church and with other Christian rulers, both secular and religious, in the 14th century.