The Canal Saint-Denis is a 6,6-kilometre long canal in Paris located in the 19th arrondissement. It connects the Canal de l'Ourcq to two municipalities belonging to the department of Seine-Saint-Denis: Saint-Denis and Aubervilliers. The canal's route has seven locks. At one end, it meets the River Seine.
The construction of the canal began after the decree issued by Napoléon Bonaparte in 1802 to speed up shipping and relieve traffic congestion on the River Seine, where many ships and barges sailed up and down the river through the centre of Paris. This was possible thanks to the involvement of the private banking firms: Roman Vassal, Lafitte, André, and Cottier, which were granted contracts to build the canals and use them for their own purposes. Furthermore, the bankers had the right to collect tolls on the canal for 99 years. The construction of the canal lasted 19 years and it was inaugurated in 1821.
The Canal Saint-Denis belongs to the Réseau des Canaux Parisiens (Parisian Canal Network), which also includes the Canal de l'Ourcq, the Bassin de la Villette, the Canal Saint-Martin, and the Bassin de l'Arsenal. Together, they form an almost 130-kilometre long network.