Proxeny or proxenia (Ancient Greek: προξενία) in ancient Greece was an arrangement whereby a citizen (chosen by the city) hosted foreign ambassadors at his own expense, in return for honorary titles from the state.
The citizen was called proxenos (πρόξενος; plural: proxenoi or proxeni, "instead of a foreigner") or proxeinos (πρόξεινος).
A common phrase is euergetes (benefactor) and proxenos (πρόξεινος τε ειη και ευεργέτης).
For example, Cimon was Sparta's proxenos at Athens and during his period of prominence in Athenian politics, previous to the outbreak of the First Peloponnesian War, he strongly advocated a policy of cooperation between the two states.
A 2024 study in the Journal of Economic History linked the presence of proxeny arrangements to increases in trade flows.