Socrates: He is at first of his usual disposition, jovial and eager to talk on the subject of virtue.  But in the second half of the dialogue we see a different Socrates, considering weaknesses in his own argument and using new methods of inquiry and argument not found in other Socratic dialogues.

Meno: A young man from one of the leading aristocratic families of Thessaly.  He is preparing to begin a corrupt career in the military and politics, which ultimately led to an untimely death at the hands of the Persian king.  His Athenian host is Anytus and during the course of this dialogue Meno challenges Socrates with a paradox of knowledge, until Socrates refutes it and Meno's doubt about inquiry is relieved. 

Anytus: Meno's host among other distinctions.  He was a democratic politician in Athens and one of Socrates' accusers at his trial.  He seems in this dialogue to have a disdain for philosophers, and Sophists in particular.  At one point he warns Socrates to mind the manner in which he speaks of people, or people will be hurt.