Zambales is a province of the Philippines located in the Central Luzon region. Its capital is Iba. Zambales borders Pangasinan to the north, Tarlac and Pampanga to the east, Bataan to the south and the South China Sea to the west. With a land area of 3,700 km², Zambales is the second largest among the seven provinces of Central Luzon. It has a population density of 150 people per square kilometer², one of the lowest in the country. The province is noted for its mangoes, which are abundant from January to April.

Zambales is served by the Subic Bay International Airport, which is located in Cubi Point in the Subic Bay Freeport Zone. The Freeport Zone is host to many tourist attractions which include casinos, beach resorts, parks, beachside huts and cottages and historical sites. The Scarborough Shoal is internationally recognized as a part of Zambales Province.

Zambales lies on the western shores of Luzon island along the South China Sea. Its shoreline is very ragged, and features many coves and inlets. The Zambales Mountains, the mountain range on the eastern part of the province occupies about 60% of its total land area. Subic Bay, in the southern end of the province, provides a natural harbor, and was chosen as the location of the U.S. Naval Base Subic Bay. The peak of Mount Pinatubo lies near the tripoint of Zambales, Pampanga, and Tarlac provinces. This volcano, once considered dormant, erupted violently in 1991 blowing off its summit, leaving a caldera (now filled with Lake Pinatubo), on the mountains of Botolan, Zambales. A vast portion of the province acquired desert-like features after being buried by more than 20 feet (6.1 m) deep of lahar.