Tonadico was a comune located in the Trentino province of the northern Italian region of Trentino-Alto Adige/Südtirol. It was situated approximately 60 kilometres east of Trento and covered an area of 89.4 square kilometres.
As of December 31, 2004, the municipality had a population of 1,429 residents. On January 1, 2016, Tonadico was merged with the municipalities of Siror, Fiera di Primiero, and Transacqua to form the new municipality of Primiero San Martino di Castrozza.