Legislative districts of Zamboanga del Sur

Prior to gaining separate representation, areas now under the jurisdiction of Zamboanga del Sur were represented under the Department of Mindanao and Sulu (1917–1935) and the historical Zamboanga Province (1935–1953).

The enactment of Republic Act No. 711 on June 6, 1952 divided the old Zamboanga Province into Zamboanga del Norte and Zamboanga del Sur and provided them each with a congressional representative.[1] Per Section 7 of Republic Act No. 711, the chartered cities of Zamboanga and Basilan formed part of Zamboanga del Sur's representation.[1] The province, along with the two cities, first elected its representative starting in the 1953 elections. Even after receiving its own city charter on June 21, 1969, Pagadian remained part of the representation of the Province of Zamboanga del Sur by virtue of Section 108 of Republic Act No. 5478.[2]

Zamboanga del Sur was represented in the Interim Batasang Pambansa as part of Region IX from 1978 to 1984. The province returned three representatives, elected at-large, to the Regular Batasang Pambansa in 1984. Basilan (established as a province in 1973) and Zamboanga City (classified as a highly urbanized city in 1983) separately elected their representatives starting that year.

Zamboanga del Sur was reapportioned into three congressional districts under the new Constitution[3] which was proclaimed on February 11, 1987, and elected members to the restored House of Representatives starting that same year.

The passage of Republic Act No. 8973 and its subsequent ratification by plebiscite on February 22, 2001 separated Zamboanga del Sur's entire third district to create the new province of Zamboanga Sibugay.[4] Per Section 7 of Republic Act No. 8973, Zamboanga del Sur's representation was reduced to two districts.[4] The former third district first elected a representative under the designation Lone congressional district of Zamboanga Sibugay beginning in the 2001 election.

The now-defunct 3rd district automatically became the representation of Zamboanga Sibugay upon its establishment in February 2001, but it was in May 2001 that this new province first elected a representative under its own name.

• City: Pagadian
• Municipalities: Aurora, Dumingag, Josefina, Labangan, Mahayag, Midsalip, Molave, Ramon Magsaysay, Sominot, Tambulig, Tukuran
• Population (2015): 602,609[5]

• Municipalities: Bayog, Dimataling, Dinas, Dumalinao, Kumalarang, Lakewood, Lapuyan, Margosatubig, Pitogo, San Miguel, San Pablo, Tabina, Tigbao, Vincenzo A. Sagun, Guipos (established 1991)
• Population (2015): 408,065[5]

• Municipalities: Alicia, Buug, Diplahan, Imelda, Ipil, Kabasalan, Mabuhay, Malangas, Naga, Olutanga, Payao, Roseller T. Lim, Siay, Talusan, Titay, Tungawan

• includes Zamboanga City, and the present-day provinces of Basilan and Zamboanga Sibugay

Notes

• includes the present-day province of Zamboanga Sibugay

• Legislative district of Mindanao and Sulu
• Legislative district of Zamboanga
  • Legislative district of Basilan
  • Legislative districts of Zamboanga City
  • Legislative districts of Zamboanga Sibugay