Bregaglia (Italian and Romansh: ) is a municipality in the Maloja Region in the canton of Grisons in Switzerland . It was formed by the 2010 merger of the municipalities of Bondo, Castasegna , Soglio, Stampa and Vicosoprano , all located in the Val Bregaglia .

Bregaglia is the only Italian-speaking municipality in Switzerland in which the majority of the population is Protestant.

Under the Carolingian dynasty Bondo belonged to the Ministerium Bergallia, which was a dependant of the early Bishops of Chur, though after 960 it was owned directly by the Bishop. The valley church of S. Maria at Castelmur is first mentioned in 988, while the village church for Bondo, S. Martino, was consecrated in 1250. During the High Middle Ages Bondo was part of several villages that were collectively known as di là dell'acqua (‘across the water’), which were part of the district of Sotto Porta/Unterporta.