Olongapo, officially the City of Olongapo, is a 1st class highly urbanized city in the Central Luzon region of the Philippines. According to the 2020 census, it has a population of 260,317 people. It is geographically situated and grouped under the province of Zambales by the Philippine Statistics Authority but governed independently from the province and it is also the largest city. Portions of the city also form part of the Subic Special Economic and Freeport Zone.