- The protagonist of the Phaedo,
and most of Plato's dialogues. Socrates is one of the most important figures in the history of Western philosophy, standing at the source of the rational tradition initiated by himself, Plato, and Aristotle. Socrates himself arguably never advanced any of his own doctrines. However, in Plato's middle and later dialogues, the figure of Socrates no longer represents the man himself. Instead, the figure of Socrates is used as a mouthpiece through which Plato advances his own views. In the Phaedo
we find Socrates a seventy-year-old man about to die, and propounding all sorts of Platonic doctrines. He is calm and contented as he faces death, confident in the good fortune that awaits him after death.
- The main interlocutor, along with Cebes, of the Phaedo.
He is a Pythagorean philosopher from Thebes who has come to speak with Socrates before his death.
- The main interlocutor, along with Simmias, of the Phaedo.
He is a Pythagorean philosopher from Phaedondas who has come to speak with Socrates before his death.
- The narrator and namesake of the dialogue. He is a handsome young man from Elis who has become enamored of Socrates and his teachings. Like Plato, the historical Phaedo dedicated himself to philosophy, and wrote Socratic dialogues in honor of his mentor. None of Phaedo's writings are with us today.
- A Pythagorean philosopher from the Peloponnesian town of Phlius. He encounters Phaedo in Phlius and asks him to tell the story of Socrates' final hours. On a couple of occasions in the dialogue, the narrative is interrupted by a brief conversation between Echecrates and Phaedo.
- An old friend of Socrates, of about Socrates' age. Crito is the main interlocutor of the Crito,
an earlier dialogue which takes place in Socrates' prison cell. In the Phaedo,
Crito does not participate much in the philosophical discussion, playing the role of best friend to Socrates more than that of interlocutor.
- Socrates' wife. Xanthippe was reputedly a shrewish and unpleasant woman. Considering the nonchalant way Socrates treats both her and his children in this dialogue, however, we should hardly be surprised. It seems that in his desire to detach himself as much as possible from the material world, Socrates has also detached himself from his family.
- The man standing guard over Socrates during his month in prison. The officer has grown very fond of Socrates, and the two have had many conversations together. When it comes time for Socrates to die, the officer tells Socrates that he is the finest man he has ever had the privilege of knowing, and bursts into tears.