Tonadico (Tonadìch in local dialect) was a comune (municipality) in Trentino in the northern Italian region Trentino-Alto Adige/Südtirol, located about 60 kilometres (37 mi) east of Trento. As of 31 December 2004, it had a population of 1,429 and an area of 89.4 square kilometres (34.5 sq mi). It was merged with Siror, Fiera di Primiero and Transacqua on January 1, 2016, to form a new municipality, Primiero San Martino di Castrozza.

The municipality of Tonadico contains the frazioni (subdivisions) Tressane and part of San Martino di Castrozza.

Tonadico borders the following municipalities: Falcade, Moena, Canale d'Agordo, Taibon Agordino, Predazzo, Siror, Voltago Agordino, Gosaldo, Sagron Mis, Transacqua and Fiera di Primiero.