The province of Zamboanga del Sur is bounded on the north by the province of Zamboanga del Norte; on the south by the Moro Gulf; on the southwest by Zamboanga Sibugay; and on the east and northeast by Lanao del Norte, Misamis Occidental, and Panguil Bay.
The original inhabitants of the Zamboanga peninsula were the Subanons, who settled along the riverbanks. The next group of settlers to arrive were Muslim migrants from the neighboring provinces. The Maguindanaoans and Kalibugans were farmers; the Tausugs, Samals, and Badjaos were fishermen; and the Maranaos were traders and artisans. The Muslim settlers also looked on mat weaving as its major occupation.
Then came an exodus of migrants from nearby provinces. Historians say that majority of them came from the Visayas, Cebu, Bohol, Negros, and Siquijor. Together with the original settlers, these pioneers helped develop Zamboanga del Sur into the abundant and culturally diverse province that it is.
Today the province comprises two congressional districts with 26 municipalities and one component city. Pagadian City, its capital, with a total of 681 barangays, has been declared as the new regional seat of Region IX.