Demetrius of Amphipolis
Demetrius of Amphipolis (Greek: Δημήτριος ὁ Ἀμφιπολίτης; fl. 4th century BC) was one of Plato's students. He is perhaps identical with the person mentioned in Plato's Testament as one of the executors of his last will.
References
Laërtius, Diogenes. . Lives of the Eminent Philosophers. Vol. 1:3. Translated by Hicks, Robert Drew (Two volume ed.). Loeb Classical Library.