Brazilian nationality law details the conditions by which a person is a national of Brazil. The primary law governing nationality requirements is the 1988 Constitution of Brazil, which came into force on 5 October 1988.

With few exceptions, almost all individuals born in the country are automatically citizens at birth. Foreign nationals may naturalize after meeting a minimum residence period (usually four years), demonstrating proficiency in the Portuguese language, and fulfilling a good character requirement.

Brazil was previously a colony and constituent kingdom of the Portuguese Empire, and local residents were Portuguese subjects. Although Brazil gained independence in 1822 and Brazilian nationals no longer hold Portuguese nationality, they continue to have favoured status when living in Portugal; Brazilians resident for at least three years are eligible to vote in Portuguese elections and serve in public office there.

Brazil is a member state of Mercosur, and all Brazilian nationals are Mercosur citizens. They have facilitated access to residence rights in all member states and most associated states of Mercosur.

Any person born in Brazil acquires Brazilian nationality at birth, with the sole exception of children of parents in the service of a foreign government, such as foreign diplomats.^[1]

A person born outside Brazil of a Brazilian parent also acquires Brazilian nationality at birth if:^[1]

• The Brazilian parent is in the service of the Brazilian government; or
• The person is registered with a Brazilian consular office; or
• The person later moves to Brazil and confirms one's nationality before a federal judge.

Between 1994 and 2007, registration with a Brazilian consular office did not confer Brazilian nationality. In September 2007, a constitutional amendment reinstituted consular registration as a means of acquiring Brazilian nationality.^[2]

Since October 2023, Brazil does not impose any restriction on dual nationality. Brazilian nationality may be lost only in the case of naturalized citizens whose naturalization is canceled by a court sentence due to fraud in their naturalization process or due to an act "against the constitutional order and the democratic state", or in the case of people who explicitly request the loss of their Brazilian nationality before a Brazilian authority as long as such loss would not make them stateless.^[1]

In its original text, the Brazilian constitution of 1988 stated that Brazilians who voluntarily naturalized in another country could lose Brazilian nationality. In 1994, a constitutional amendment modified this provision, stating that Brazilians who acquired another nationality could lose Brazilian nationality, except if the other nationality was acquired by origin (by birth or descent) or if naturalization was required by the other country for the person to remain residing there or to exercise civil rights.^[2] In practice, the Brazilian government only used this provision to revoke Brazilian nationality in very few cases, such as for the purpose of extradition, as the Brazilian constitution does not allow extradition of its own citizens by birth.^[13][14] In 2023, another constitutional amendment eliminated the possibility of loss of Brazilian nationality due to acquisition of another nationality.^[2]

People who requested the loss of their Brazilian nationality, or who lost it due to acquiring another nationality under the previous constitutional provision, may request the reacquisition of Brazilian nationality.^[1][3][4][5]

Since May 2016, Brazil does not require naturalized citizens to renounce their previous nationality.^[11][12][4]

Brazilians who also have another nationality are allowed to enter and leave Brazil with the passport of the other country. If they also provide a Brazilian identity card, they are admitted as Brazilians without restriction, otherwise they are admitted as visitors of their other nationality for their usual limited stay.^[15] However, usually the latter case is only possible if Brazil does not require a visa for visitors of such nationality. Brazil only issues visas to its dual citizens in exceptional circumstances, such as for those who work in foreign government jobs that prohibit the use of a Brazilian passport.^[16]

In 1822, Brazil declared independence from Portugal and established the Empire of Brazil under Pedro I, who had been living in exile in the country since 1808.^[29] The nation's first constitution was adopted in 1824^[30] and provided that Brazilian citizens were free-born or emancipated men who were born in Brazil, unless their father was a foreigner in the service of another nation. Legitimate children born abroad to a Brazilian father, or illegitimate children born to a Brazilian mother, could establish nationality by becoming domiciled in Brazil;^[31] however residence was waved if their father was in government service. Portuguese nationals and naturalized foreigners who resided in Brazil at the time of independence were naturalized by residence in the empire. Citizenship could be lost if one was naturalized in another country or accepted employment or honors from foreign governments without the approval of the crown.^[32]

In 1860, to eliminate Brazilian nationality law conflicts with European legislation, Brazil passed Decree 1,096, which clarified the status of children born in Brazil to foreign parents who were not in government service, and married women. The decree specified that minor children shared family nationality, but upon reaching their majority would be entitled to Brazilian nationality and rights of citizens. Article 2 provided that upon marriage a woman took the nationality of her husband, but could repatriate if her husband died and she re-established residence in Brazil.^[33] Immigration legislation passed in 1890 barred people of African or Asian descent from the country. The law was modified in 1892 to allow Chinese and Japanese laborers.^[34] The 1824 constitution remained in force until the First Brazilian Republic adopted the Constitution of 1891. The republican constitution was modeled on the United States Constitution.^[35] Despite feminists' efforts the Constituent Congress denied them the rights of citizens.^{[36][37][Notes 1]} It provided, as amended in 1926, that children born in Brazil were birthright nationals of the country unless their foreign parents were residing in Brazil because of government service to another nation. The legitimate child born abroad to a Brazilian father was considered to have his father's nationality as long as he established a home in Brazil. The domicile requirement could be waived for a child whose father was employed abroad in service to the government. Only the illegitimate child born abroad to a Brazilian mother could derive nationality from her, on the condition of establishing residency in Brazil.^[41]

Decree No. 6,948, of 14 May 1908, stipulated that a foreigner, regardless of gender, who married a Brazilian, or who had Brazilian children, and resided in Brazil derived Brazilian nationality unless they declared in the proper legal manner that they chose to retain their original nationality.^[42] In 1932, Decree 21,076, which established the first Electoral Code of Brazil, outlined in article 2 that the rights of citizenship were not dependent on sex, and in article 3(b) that Brazilian women could not lose their nationality as a result of marriage.^[42][43] In 1933, Gilberto Amado [pt] and Lucillo Antonio da Cunha Bueno, the Brazilian delegates to the Pan-American Union's Montevideo conference, signed the Inter-American Convention on the Nationality of Women, which became effective in 1934, without legal reservations.^[44] That year, a new constitution was adopted, keeping most of the provisions of naturalization specified by its 1891 predecessor. It specified that nationality could be lost by obtaining dual citizenship.^[45] From 1907 to 1934, racial exclusions were not specified in immigration law, but in the latter year, a quota system was devised to limit immigration from certain countries.^[46] Since 1995, consent is required for loss of Brazilian citizenship for dual nationals.^[47]

• Brazilian identity card
• Brazilian passport
• Cadastro de Pessoas Físicas
• History of Brazilian nationality
• Visa policy of Brazil
• Equality Statute between Brazil and Portugal