Zambales, officially the Province of Zambales (Sambal: Probinsya nin Zambales; Ilocano: Probinsia ti Zambales; Pangasinan: Luyag na Zambales; Kapampangan: Lalawigan ning Zambales; Tagalog: Lalawigan ng Zambales), is a province in the Philippines located in the Central Luzon region. Its capital is Iba, which is located in the middle of the province. Olongapo is the largest city of the province wherein it is geographically located but politically independent.

Zambales borders Pangasinan to the north and northeast, Tarlac to the east, Pampanga to the southeast, Bataan to the south and the South China Sea to the west. With a total land area of 3,830.83 square kilometres (1,479.09 sq mi) (including the independent city of Olongapo), Zambales is the second largest among the seven provinces of Central Luzon after Nueva Ecija. The province is noted for its mangoes, which are abundant from January to April.

Zambales does not have a functional airport; the closest functional airport is Clark International Airport in Angeles City in the neighbouring province of Pampanga. Subic Bay International Airport, which is located in Cubi Point (geographically and politically located inside Morong, Bataan) in the Subic Bay Freeport Zone is no longer functional for domestic and international flights.

The Freeport Zone (SBFZ) is host to many tourist attractions which include casinos, parks, malls, beach-side huts, cottages and resorts, as well as historical sites.

The name of the province is derived from "Zambales", the Hispanized name of the Sambal people. The Sambal were the original dominant ethnic group of the region.

The Spanish first explored the area in 1572, led by Juan de Salcedo. Off Cape Bolinao (now part of Pangasinan), he and his men liberated a Zambal chieftain and his followers from a Chinese pirate ship. This act gained the natives' goodwill. Shortly thereafter, the province was organized. Among the earliest towns founded were Masinloc (1607), Subic (1607), Iba (1611), Santa Cruz (1612), and Botolan (1736). Zambales was originally derived from 2 parts: the southern area from Pampanga and the northern area from Pangasinan.

During the Spanish period, a 1774 map was made, which clearly named Scarborough Shoals as Panacot Shoal, a feature under complete sovereignty of Spanish Philippines, specifically of Zambales. The shoal's current name was chosen by Captain Philip D'Auvergne, whose East India Company East Indiaman Scarborough briefly grounded on one of the rocks on September 12, 1784, before sailing on to China. When the Philippines was granted independence in the 19th century and 20th century, Scarborough Shoal was passed by the colonial governments to the sovereign Republic of the Philippines. By the end of the 1700s, Zambales had 1,136 native families and 73 Spanish Filipino families.

Masinloc became the province's first capital. However, the capital was moved among the last three towns above during its history before finally settling in Iba, due to its strategic location. Seven of the province's original northern towns, which included Bolinao, Infanta, San Isidro, now Burgos, Anda, Bani, Agno and Alaminos were later transferred under the jurisdiction of Pangasinan because of their distance from the capital. The first civil governor of Zambales during the colonial American era was Potenciano Lesaca from 1901 to 1903.