West Sumatra (Indonesian: Sumatera Barat, abbreviated to Sumbar) is a province of Indonesia. It lies on the west coast of the island Sumatra. It borders the provinces of North Sumatra (Sumatera Utara) to the north, Riau and Jambi to the east, and Bengkulu to the southeast. It includes the Mentawai Islands off the coast. The capital of the province is Padang.

West Sumatra is one of the earthquake prone areas in Indonesia, due to its location in the tectonic slab located between the confluence of two major continental plates (the Eurasian plate and Indo-Australian plate) and Great Sumatran fault, plus the activity of the active volcanoes. Large earthquakes that occurred recently in West Sumatra earthquake is 2009 Sumatra earthquake and the October 2010 Sumatra earthquake.

The history of West Sumatra is related to the history of the Minangkabau people. Archaeological evidence indicates that the area surrounding the Limapuluh Koto regency forms the first area inhabited by the Minangkabau. Limapuluh Koto regency covers a number of large rivers which meet at the eastern part of the Sumatran coastline and provided sailing transportation until the end of the last century. The Minangkabau ancestors were believed to have arrived via this route. They sailed from Asia (Indo-China) via the South China Sea, crossing the Malacca Strait and later settled along the Kampar, Siak and Indragiri (or Kuantan) rivers. Some lived and developed their culture and traits around the Limapuluh Koto regency.