Diadochos of Photiki (Greek: Διάδοχος Φωτικής) was a fifth-century Christian ascetic whose works are included in the Philokalia.

Scholars have acknowledged his great influence on later Byzantine saints such as Maximos the Confessor, John Climacus, Symeon the New Theologian, and in general the Hesychast movement of the 14th century.

He has also had great influence in the West via the work, "On the Contemplative Life" (De vita contemplativa) of Julianus Pomerius (†498).

This, however, is not the case, as Macarius' role was merely to salvage from within the Messalian heresy those who were there by chance or just misled by the ambiguous discourses of the unorthodox doctrine.

[citation needed] In the 100 Chapters, Diadochos shows himself as a bishop worried about the orthodoxy of his flock and as a clear actor in the spiritual fights of his time.

Discourse deriving from the wisdom of this world, on the other hand, always provokes self-esteem; because it is incapable of granting us the experience of spiritual perception, it inspires its practitioners with a longing for praise, it being nothing but the fabrication of conceited men.