Neilos Kabasilas (also Nilus Cabasilas; Greek: Νεῖλος Καβάσιλας Neilos Kavasilas), was a fourteenth-century Greek^[1] Palamite theologian who succeeded Gregory Palamas as Metropolitan of Thessalonica (1361–1363). Neilos, who was called Nicholas as a layman, has often been confused with his nephew, the more famous Nicholas Kabasilas, best known for his Commentary on the Divine Liturgy

Neilos was a teacher of the famed translator of Thomas Aquinas into Greek, Demetrios Kydones. As a theologian, his most important works are a Theological Rule in defense of the essence-energies distinction and a series of discourses against the Filioque (the Latin teaching on the procession of the Holy Spirit).