Which language is the sole official language of Portugal and Brazil?

Portuguese is the sole official language of both Portugal and Brazil.

Portuguese developed on the western Iberian Peninsula from varieties of Vulgar Latin. It spread worldwide through Portuguese exploration, settlement, trade, and colonial rule, becoming the official language of Brazil and several countries in Africa and Asia.

Portugal and Brazil share the language, but their standard varieties differ in pronunciation, vocabulary, and some grammar. Brazilian Portuguese has the world’s largest Portuguese-speaking population, while European Portuguese preserves pronunciation and usage patterns associated with Portugal.

Portuguese is also an official language in countries including Angola, Mozambique, Cape Verde, Guinea-Bissau, São Tomé and Príncipe, and Timor-Leste. It is one of the working languages of several international organizations. Portuguese should not be treated as identical to Spanish: the languages are related Romance languages, but their sounds, vocabulary, and grammar are distinct.