The Guil is a 51.6-kilometre (32.1 mi) long river in the Hautes-Alpes département, southeastern France. Its drainage basin is 727 km2 (281 sq mi). Its source is several small streams which converge into the lake Lestio, at Ristolas. It flows generally west, through the Queyras. It is a left tributary of the Durance into which it flows at Guillestre.