Transacqua was a comune (municipality) located in the Trentino province of the northern Italian region of Trentino-Alto Adige/Südtirol. It was situated approximately 60 kilometres east of the city of Trento.
As of December 31, 2004, the municipality covered an area of 35.6 square kilometres and had a population of 2,007 residents. On January 1, 2016, Transacqua was merged with the municipalities of Siror, Tonadico, and Fiera di Primiero to form the new municipality of Primiero San Martino di Castrozza.