The Areani were agents in Imperial Roman military units based in Roman Britain during the later part of the Roman occupation of the island. They were used both as scouts for the legions and as undercover spies. Many of them were mercenaries; at the time of the Great Conspiracy, which they helped instigate, a good deal of them were sailors. Due to their participation in the Conspiracy, Count Theodosius disbanded them.

They are sometimes (inaccurately) called Arcani.