Agathon of Samos was a 5th-century BCE historian from the island of Samos. No details of his life or education survive beyond this origin.

His only known work is On Siphnos, a historical account of the island of Siphnos. The text is lost, preserved only in fragmentary citations by later authors such as Athenaeus.

Agathon’s significance rests on his place among the early Greek local historians, or horographers, who documented regional myths and antiquities. His fragments contribute to the fragmentary record of Greek historiography preceding Herodotus and Thucydides.