Thucydides's History of the Peloponnesian War features a rich array of characters since the book maps out the decades-long armed conflict between the Delian League (led by the Athenians) and the Spartan League.

The work features reports of one hundred forty one speeches from prominent political and military figures, and these are the primary 'characters' in this work which is nominally a history but could also be classified as philosophy or literature.

Book One begins with Minos, the legendary ruler of Crete during the Minoan Civilization. Thucydides then describes the characters involved in the Trojan War: Menelaus, Agamemnon, Helen, Paris, Hector, and Achilles. Much of the first book is similarly given over to figures from the corpus of Greek myths. Later, he moves on to figures who are non-mythical, such as Ameinocles of Corinth. Cyrus II, the King of Persia, also features in Book I as does Darius I. We are also introduced to Croseus, King of Lydia. Some famous Athenians in Book I include Themistocles and Ephialtes. Thucydides discusses the famous tyrant Peisistratus and the dynasty that followed him.

Listing all the characters would require a book of its own, so here are some of the important ones in addition to the ones mentioned in the previous paragraph: Sthenclaidas of Sparta, Pericles of Athens (whose funeral oration remains influential), Astymachus, Lacon, Peithias, Nicostrasus, Nicias, and Alcibiades.