Portuguese (português or língua portuguesa) is a Romance language that grew from the Latin descended Galician-Portuguese language that was spoken in the mediaeval Kingdom of Galicia, whose territory is now divided between northern Portugal, Galicia and Asturias. It also absorbed influences from the Romance and Arabic languages spoken in the areas that were conquered by the Portuguese reconquista. It was spread worldwide in the 15th and 16th centuries as Portugal established a colonial empire (1415–1999) that included Brazil in South America, Goa and other parts of India, Macau in China, Timor in South-East Asia and the five African countries that make up the PALOP lusophone area: Cape Verde, Guiné-Bissau, São Tomé e Príncipe, Angola and Mozambique. It was used as the exclusive lingua franca on the island of Sri Lanka for almost 350 years. During that time, many creole languages based on Portuguese also appeared around the world, in Africa, Asia, and the Caribbean.

With over 260 million speakers, is the fifth most spoken language in the world, the most widely spoken in the southern hemisphere, and the third most spoken in the Western world. In addition to Brazil and Portugal, it is used in Angola, Cape Verde, Guinea-Bissau, Macau, Mozambique, São Tome and Principe, East Timor and (since 2007) Equatorial Guinea, as well as in the former territories of Portuguese India (Goa, Daman, Isle of Angediva, Simbor, Gogol, Diu and Dadra and Nagar Haveli) and in small communities that were part of the Portuguese Empire in Asia as Malacca, Malaysia and East Africa as Zanzibar, Tanzania. It has official status in the European Union (EU), Mercosur (Mercosul in Portuguese), the African Union, the Organization of American States (OAS), the Latin Union, the Community of Portuguese Language Countries (CPLP) and the Association of National Olympic Committees of Portuguese Official Language (ACOLOP).

Like other languages, Portuguese has experienced a historical evolution, being influenced by many other languages and dialects, as it reached the form known today. Contemporary Portuguese comprises several dialects and sub-dialects (subfalares), often very distinct, and two internationally recognized standards (European Portuguese and Brazilian Portuguese). At present, Portuguese is the only language spoken in the Western world with over a hundred million people with two official orthographies.