The town of Iba, originally known as the village of Paynauen, was established in 1611 by the Recollect missionaries, Father Rodrigo de San Miguel and Father Andres del Espiritu Santo. Initially located near Fort Playa Honda, it was moved in 1680 by the Dominicans to its current location and renamed Iba. This town eventually became the capital of Zambales province.

Iba is notable for being the hometown of several prominent figures. Juan Mandy, a member of the Malolos Congress, hailed from here. Silverio Apostol, who served as the Acting Secretary of Agriculture in 1922, also came from Iba. Gregorio Anonas, a representative from 1928 to 1933, later became the manager of the Metropolitan Water District (1934-1938) and the National Development Company (1938-1946).

Additionally, Iba is the birthplace of Ramon Magsaysay, who became the President of the Philippines in 1953.