Hilarius (floruit 408) was a politician of the Western Roman Empire.

Hilarius is known to be the praefectus urbi of Rome in 408. He is attested in office on January 15 of that year by a law preserved in the Codex Theodosianus. He has been sometimes identified with a Hilarius Praetorian prefect of Gaul in 396, but this identification is rejected by historians on the fact that the urban prefecture was a lesser office than the praetorian one.

Bibliography

• Arnold Hugh Martin Jones, John Robert Martindale, J. Morris, "Hilarius 2", The Prosopography of the Later Roman Empire, Cambridge University Press, 1971, ISBN 0-521-07233-6, p. 563.