Gaël is a commune in the Ille-et-Vilaine department in Brittany in northwestern France. It lies southwest of Rennes between Saint-Mée…Gaël is a commune in the Ille-et-Vilaine department in Brittany in northwestern France. It lies southwest of Rennes between Saint-Méen-le-Grand and Mauron. In the 18th century, a fair was held twice a year in August and October.