Lapuyan is a coastal municipality in the province of Zamboanga del Sur.

The municipality has a land area of 329.00 square kilometers or 127.03 square miles which constitutes 7.34% of Zamboanga del Sur’s total area. Its population as determined by the 2020 Census was 27,737. This represented 2.64% of the total population of Zamboanga del Sur province, or 0.72% of the overall population of the Zamboanga Peninsula region. Based on these figures, the population density is computed at 84 inhabitants per square kilometer or 218 inhabitants per square mile.