Chaves is a city and a municipality (called "concelho" in Portuguese) in Portugal, located in the district of Vila Real. The city is the most populous of the district and the municipality is the second most populous in the district. It is located 10 km south of the Spanish border and just 22 km south of Verín. Aquae Flaviae is the ancient Roman name for this city.

The town has always had great historical importance, being the site of an important Roman garrison and later being in the forefront of resistance during the Napoleonic invasions of the early nineteenth century. In Portuguese military history Chaves is especially famous for two battles: the siege of Chaves by French forces in 1807 and the Royalist attack on Chaves led by Henrique Paiva Couceiro in 1912.

Chaves is a town of fortifications. There is the keep of a medieval castle and two forts, Forte São Francisco and Forte São Neutel, both built in the 17th century. Nearby, two medieval fortifications still exist - the Torre (tower) de Sto. Estêvão, in the plain, and the Castelo (castle) de Monforte, in the mountains. The original Roman bridge in Chaves crossing the Tamega still stands with its stone arches and is the most important tourist site of the town. The hot springs (73 degrees Celsius)of Chaves have been famous since Roman times and today many people come to the town to take the water cure.