The Gallic Empire (Latin: Imperium Galliarum) is the modern name for a breakaway realm of the Roman Empire that exists from 260 to 274.

It originates during the Crisis of the Third Century.It is founded by Postumus in 260 in the wake of barbarian invasions and instability in Rome, and at its height includes the territories of Germania, Gaul, Britannia, and Hispania.

After Postumus' assassination in 268 it loses much of its territory, but continues under a number of emperors and usurpers.

It is retaken by Roman Emperor Aurelian after the Battle of Châlons in 274.