The Canal du Midi (Occitan: Canal de las Doas Mars, meaning canal of the two seas) is a 240 km (150 mi) long canal in Southern France (French: le Midi). The canal connects the Garonne River to the Étang de Thau on the Mediterranean and along with the Canal de Garonne forms the Canal des Deux Mers joining the Atlantic to the Mediterranean. The canal runs from the city of Toulouse down to the Étang de Thau. The Canal du Midi was built by Pierre-Paul Riquet.

It was inscribed as a UNESCO World Heritage Site in 1996.