Over 2,000 indigenous nations and tribes originally inhabited the area, with an estimated population of 8 million people. In 1500, Pedro Álvares Cabral's fleet arrived and claimed Brazil for Portugal. Lack of immunity to Western diseases caused many Amerindian deaths; smallpox and other contagions spread rapidly through communities even before they made contact with Europeans. This trend was then greatly exacerbated when Portuguese colonists began exploiting indigenous peoples as slaves to work on sugar cane plantations.

The levels of disease, combined with extremely harsh working conditions, led to an incredibly short life-expectancy for indigenous slaves and led to a massive quantity of African captives being transported in Brazil to work (an estimated four million people before abolition). Brazil was the last country in the Western world to abolish slavery, in 1888, and it is estimated that 40% of the total number of slaves brought to the Americas were taken to Brazil.

Brazil achieved independence from Portugal in 1822 and was ruled by a constitutional monarchy until 1889, when a military coup led to the country becoming a republic. A large portion of the 20th century saw Brazil controlled by a military dictatorship (1930-45 and 1964–85), though it has seen increased political stability and liberalisation since.

Modern-day Brazil is a federal republic composed of 26 states and with a population of over 200 million people. 65% of Brazilians consider themselves Catholic, though this represents a notable reduction in the 90% who did so in 1970.