Flavius Constans (floruit 412–414) was a general of the Eastern Roman Empire.
Constans was magister militum per Thracias in 412. In 414 he held the consulship (possibly while he still was magister militum); he took office in Constantinople.
His name is a clue of a potential relationship to Flavius Constantius, his Western colleague in the consulate and later Western Emperor with the name of Constantius III; however the sources do not mention any relationship between the two.