Iba is a coastal municipality in the province of Zambales. It serves as the provincial capital.
The municipality has a land area of 153.38 square kilometers or 59.22 square miles which constitutes 4.22% of Zambales’s total area. Its population as determined by the 2020 Census was 55,581. This represented 8.56% of the total population of Zambales province, or 0.45% of the overall population of the Central Luzon region. Based on these figures, the population density is computed at 362 inhabitants per square kilometer or 939 inhabitants per square mile.