The praetorian prefecture of the Gauls (Latin: praefectura praetorio Galliarum) is one of four large prefectures into which the Late Roman Empire is divided after the death of Constantine I in 337, when the empire is split up among his sons and Constantine II receives the rule of the western provinces, with a praetorian prefect as his chief aide.

The prefecture comprises not only Gaul but also Upper and Lower Germany, Roman Britain, Spain and Mauretania Tingitana in Africa.

Its territory overlaps considerably with what was once controlled by the short-lived Gallic Empire in the 260s.After the permanent partition of the Empire in 395 into West and East spheres of control, the prefecture of Gaul continues to belong to the Western Roman Empire.

Augusta Treverorum (present-day Trier in Germany) serves as the prefecture's seat until 407 (or, according to other estimates, in 395), when it is transferred to Arelate (Arles).