The Federal District (Portuguese: Distrito Federal [dʒisˈtɾitu fedeˈɾaw] ^ⓘ) is one of 27 federative units of Brazil. Located in the Center-West Region, it is the smallest Brazilian federal unit and the only one that has no municipalities, being divided into 35 administrative regions. The federal capital of Brazil, Brasília, which is also the seat of government of the Federal District, is located in its territory. The Federal District is almost completely surrounded by the state of Goiás, but it shares a small border with Minas Gerais.

From the first republican constitution there was already a device that foresaw the move of the federal capital from Rio de Janeiro, at that time in the former Federal District (1889–1960), to the interior of the country. In 1891 the Exploration Commission of the Central Highlands of Brazil was appointed, led by astronomer Luiz Cruls and composed of doctors, geologists and botanists, who made a study on topography, climate, geology, flora, fauna and other material resources of the region of the Central Highlands The area was known as Quadrilateral Cruls and was presented in 1894 to the Republican Government.

In 1922 a commission of the Federal Government established the location in Goiás, but the project was closed. Only in 1955, during a few elections, the then presidential candidate Juscelino Kubitschek said he would transfer the capital. Elected president, he established the construction of Brasília as a meta-synthesis of his Plano de Metas.

In 1956, after being elected to the presidency, JK, on his own initiative, sent a message to Congress proposing the creation of the New Capital Urbanization Company (Novacap). After the congress approved the project, in September of the same year, the president signed the law that created the company.

As a result, Novacap, a public company, was given the task of planning and executing the construction of the federal capital in the region delimited by General José Pessoa. After a public competition to select the city's pilot plan, a judging committee chose the urban design by architect Lúcio Costa, which was unanimously approved by the Chamber of Deputies and the Senate. This also made the name Brasília official, as well as the choice of Oscar Niemeyer as architect and Joaquim Cardozo as structural engineer.

Construction began that same year, under the supervision of Oscar Niemeyer and Israel Pinheiro. The Bandeirante Nucleus was then formed, with candangos (workers who worked on the construction of Brasília, initially from Goiás, Minas Gerais and mainly the Northeast). Earthworks began in November 1956. Thirty thousand workers built Brasília in 41 months. Israel Pinheiro was appointed the first mayor of the Federal District on April 17, 1960, shortly before its inauguration on April 21, 1960, the date chosen by Juscelino Kubitschek in honor of Tiradentes.

The capital of Brazil was transferred from Rio de Janeiro to Brasília on 21 April 1960 and its new territory, split off from Goiás state on the border with the Minas Gerais state, became the current Federal District. After the transfer the old Federal District, containing the city of Rio de Janeiro, became the state of Guanabara. This state existed from 1960 until 1975, when it merged with the state of Rio de Janeiro. With the merger the capital of Rio de Janeiro state was transferred back from Niterói to Rio de Janeiro itself (as it had been until 1834 when the empire created the Neutral Municipality).

According to the IBGE census of 2007, there were 2,393,000 people residing in the Federal District. The population density was 410.9 inhabitants per square kilometre (1,064/sq mi).