The Rance (French pronunciation: [ʁɑ̃s] ; Breton: Renk, [ˈrẽŋk]) is a river of northwestern France. It is 103.6 km (64.4 mi) long. The semi-tidal river flows into the English Channel between Dinard and Saint-Malo.

Before reaching the Channel, its waters are barred by a 750 metre long dam forming the Rance tidal power plant.

The river is linked to the Vilaine by means of the Canal d'Ille-et-Rance.

Départements and towns along the river:

• Côtes-d'Armor: Collinée, Caulnes, Dinan
• Ille-et-Vilaine: Dinard, Saint-Malo

Tributaries of the Rance include:

• Croqueloir
• Clergé
• Fremeur
• Quinéford

This river has moderate turbidity and its brownish water is somewhat low in velocity due to the slight gradient of the watercourse; pH levels have been measured at 8.13 within the city of Dinan and electrical conductivity of the waters have tested at 33 micro-siemens per centimetre. At this reference location, summer flows are typically in the range of 14 cubic metres per second (500 cu ft/s).