Flavius Hierius (Greek: Ίέριος; floruit 425–432) was a politician of the Eastern Roman Empire.
Hierius was Praetorian prefect of the East a first time from 425 to 428, then a second time in 432.
In 427, he also held the consulate, with Ardabur as a colleague, both chosen by the Eastern court.
In 427 he also restored and dedicated the Baths of Constantine (also called "of Theodosius").