The March (also margraviate or marquisate) of Montferrat is a frontier march of the Kingdom of Italy during the Middle Ages and a state of the Holy Roman Empire.

Originally part of the March of Western Liguria (Marca Liguriae Occidentalis) established by King Berengar II about 950 during a redistribution of power in the northwest of his kingdom, the area of Montferrat—a territory in Piedmont south of the Po and east of Turin—is constituted as the marca Aleramica ("Aleramic march") for his son-in-law Aleramo.

The earliest secure documentation of Aleramo and his immediate family is derived from the founding charter of the Abbey of Grazzano in 961, occasioned by the recent death of Aleramo's son Gugliemo.

In 1574, Montferrat is raised to a Duchy by Maximilian II, Holy Roman Emperor.