According to oral tradition, the first name of the settlement was Mestre d'Armas because a blacksmith, expert in the art of fixing and dealing with weapons (armas), settled in the region.

[citation needed] The founding of the nucleus, which gave birth to Planaltina is attributed to José Gomes Rabelo, a rancher who transferred from the former capital of the province of Goiás, to a small lake called Lagoa Bonita, later extending his land to the dwelling known as "Mestre d'Armas".

Dona Marta Carlos Alarcão ordered a wooden statue of the saint from Portugal, which was later substituted for a larger one when the church was expanded.

[citation needed] After 1917, the town began to attract small industries and dried meat producers, tanneries, shoe factories, a hydroelectric plant and a road linking Planaltina to Ipameri.

[citation needed] The national President, Epitácio Pessoa, made a decree establishing the Founding Stone and designated the engineer Balduino Ernesto de Almeida, Director of the Railroad in Goiás, to lead the mission.

[citation needed] On 7 September 1922, with a caravan consisting of 40 people the founding stone was placed on Centenário Hill, located 9 km from the town.

[citation needed] In the decade of the 1930s, there was a cooling off of the movement to relocate the capital, but in 1945 the question was taken up again and Planaltina played host to a commission headed by President Eurico Gaspar Dutra.

[citation needed] After 1966 Planaltina underwent periodic changes with the establishment of housing tracts (loteamentos) to receive people who could not be settled in the Brasília.

Originally a municipality of the state of Goiás dating from before the eighteenth century, it had part of its territory integrated into the new Federal District, when the capital was transferred from Rio de Janeiro to Brasília in 1960.

To serve as the seat of the remaining municipality belonging to the state of Goiás, a small city was built, which also has the name Planaltina, but popularly known as Brasilinha (little Brasília).

In recent years it has grown haphazardly with many new housing areas being built to accommodate landless and homeless migrants who arrive daily looking for work in Brasília.

[citation needed] According to research carried out by Companhia do Planalto Central (Codeplan) in 2004, more than 80% of the inhabitants of the urban area of Planaltina live without rain drainage and 45% do not have a sewage system.

[citation needed] The municipality contains the 10,547 hectares (26,060 acres) Águas Emendadas Ecological Station, a fully protected conservation unit that dates back to 1968 and preserves samples of various types of cerrado vegetation.

[citation needed] The Igrejinha de São Sebastião was declared a monument by Patrimônio Histórico e Artístico do Distrito Federal, in 1980, and today it is no longer used for religious celebrations.