West Sumatra is a province of Indonesia. It is on the west coast of the island of Sumatra and includes the Mentawai Islands off that coast. West Sumatra borders the Indian Ocean to the west, as well as the provinces of North Sumatra to the north, Riau to the northeast, Jambi to the southeast, and Bengkulu to the south. The province has an area of 42,119.54 km2 (16,262.45 sq mi),or about the same size as Switzerland,with a population of 5,534,472 at the 2020 census. The official estimate at mid 2022 was 5,640,629. The province is subdivided into twelve regencies and seven cities. It has relatively more cities than other provinces outside Java, although several of them are relatively low in population compared with cities elsewhere in Indonesia. Padang is the province's capital and largest city.

North Sumatra is a province of Indonesia located in the northern part of the island of Sumatra. Its capital and largest city is Medan. It is bordered by Aceh on the northwest and Riau and West Sumatra on the southeast, with two different coastlines located on the Indian Ocean and the Strait of Malacca, and a maritime border with Malaysia to the east. North Sumatra is Indonesia's fourth most populous province after West Java, East Java, and Central Java, and is also the most populous province outside of Java Island. North Sumatra is also the third-largest province in area on the island of Sumatra after South Sumatra and Riau provinces. It covers an area of 72,460.74 km2, which is approximately the same size as Sierra Leone or Scotland or Maine.