Pasion (Greek: Πασίων) (alternatively spelt Pasio ) was a slave in Ancient Greece from the 4th century BC, who rose to become a successful banker and Athenian citizen. He was owned by the bankers Antisthenes and Archestratus, who had a bank at the Piraeus, the harbor five miles out of Athens. During his slavery, he quickly rose to chief clerk (Argyramoibos) in charge of a money-changing table at the port, and proved so valuable that he was finally freed as reward for his faithful service. When his owners retired, Pasion inherited the bank and established a shield factory. The gifts he provided Athens included one thousand shields and a trireme. Ultimately, Pasion was granted Athenian citizenship and started investing in real estate in order to accumulate more wealth. When he became too old to work, Pasion had Phormio, another slave, take care of the bank. When Pasion died in 370 BC his widow married Phormio in order to keep the bank in the family. Pasion had two sons with his wife Archippe: Apollodorus and Pasikles.