Tambulig is a coastal municipality in the province of Zamboanga del Sur.
The municipality has a land area of 130.65 square kilometers or 50.44 square miles which constitutes 2.91% of Zamboanga del Sur’s total area. Its population as determined by the 2020 Census was 37,480. This represented 3.57% of the total population of Zamboanga del Sur province, or 0.97% of the overall population of the Zamboanga Peninsula region. Based on these figures, the population density is computed at 287 inhabitants per square kilometer or 743 inhabitants per square mile.