Terlago (Terlác in local dialect) was a comune (municipality) in Trentino in the northern Italian region Trentino-Alto Adige/Südtirol, located about northwest of Trento. As of 31 December 2004, it had a population of 1,571 and an area of . It was merged with Padergnone and Vezzano on January 1, 2016, to form a new municipality, Vallelaghi.
Terlago borders the following municipalities: Fai della Paganella, Molveno, Lavis, Zambana, Andalo, Trento and Vezzano.
Terlago's name derives from the Latin trilacum -- "the three lakes"âÂÂwhich refers to nearby Lake Lamar, Lake Terlago, and Lago Santo.