Gonzaga is a first class municipality in the province of Cagayan, Philippines. According to the 2015 census, it has a population of 38,892 people. The 2012 film The Mistress, starring John Lloyd Cruz and Bea Alonzo, was partly shot in the town. ^ "Region II ". Census of Population : Total Population by Province, City, Municipality and Barangay. PSA. Retrieved 20 June 2016.