San Mateo (pronounced locally as /sænˈmäCHō/ not /sæn mə-tay-oh/ Spanish: St. Matthew) is a first class municipality in the province of Isabela, Philippines. According to the 2010 census, it had a population of 60,792 people.Aside from being the "munggo" capital, San Mateo is gearing to become the Philippines' first agro-ecological city.