The Naviglio Grande is a canal in Lombardy, northern Italy, connecting the Ticino river near Tornavento (23 km (14 mi) south of Sesto Calende) to the Porta Ticinese dock, also known as the Darsena, in Milan.

Probably originating as a ditch dug in 1157 between Abbiategrasso and Landriano as a defense against Frederick Barbarossa, it was one of the largest medieval engineering projects, allowing development of commerce, transport and agriculture.

In 1179 however, a dam was constructed and water from the Ticino was directed towards Turbigo, Castelletto di Cuggiono, Bernate and Boffalora reaching Gaggiano in 1233.

Although intended mostly for irrigation, pontoons called cobbie quickly began using the canal to take salt, grain, wine, manufactured goods, fabric, tableware, manure and ash upriver to Lake Maggiore and Switzerland, bringing back livestock, cheese, hay, coal, lumber, sand, marble and granite.

This confirmed the canal to be the most valuable form of transport of Milan, and proved that the network could be expanded to serve the whole region, especially in transferring troops rapidly between defensive castles.