- region of WC Spain, on the Portuguese border: 16,063 sq mi (41,603 sq km)
- region of W Portugal, on the Atlantic: chief city, Lisbon
- A historical region and former province of western Portugal surrounding Lisbon.
- A historical region of west-central Spain bordering on Portugal. Reconquered from the Moors in the 1100s and 1200s, it was frequently a battlefield in the Spanish territorial wars with Portugal and in the Peninsular War fought between France and Great Britain (1808–1814).
- Alternative form of Extremadura.