Vagli Sotto is a comune (municipality) in the Province of Lucca in the Italian region of Tuscany, located about 90 km northwest of Florence and about 35 km northwest of Lucca. Sotto borders the following municipalities: Camporgiano, Careggine, Massa, Minucciano, Stazzema. The Lake of Vagli, created by a dam in 1947, and the abandoned village of Fabbriche di Careggina, are located nearby. The town contains the Romanesque church of San Regolo.