Tabatinga, originally Forte de São Francisco Xavier de Tabatinga, is a municipality in the Três Fronteiras area of Western Amazonas. It is in the Brazilian state of Amazonas. Its population was 67,182 (2020) and its area is 3,225 km<sup>2</sup>.
Together with the neighbouring Colombian city of Leticia and the Peruvian city of Santa Rosa de Yavari, the urban area has more than 100,000 residents spread along the Amazon River. The first Portuguese settlement in the area was founded in the 18th century as a military outpost. It became an autonomous municipality on February 1, 1983. having its meaning designated as white clay or soil white. It is believed that the indigenous people referred to the region with that name because of the white clay found abundantly at the bottom of the region's rivers. In the Tupi Guarani, the word also means small house. Fernando da Costa Ataíde Teives was responsible for the creation of a military post in the region and also created a border post between the domains of the Kingdom of Portugal and Spain, alongside other military posts. The town of São Francisco Xavier de Tabatinga was then established. Of the three main colonial border settlements (São Francisco Xavier de Tabatinga, Vila Ipiranga and Vila Bittencourt), only the first was actively developing. On June 28, 1866, near the village, the border between Brazil and Peru was drawn. Until then, the region was administratively subordinated to the municipality of São Paulo de Olivença, however many few municipalities were established in the region. In 1898, with the dismantling of the territory of São Paulo de Olivença and the emancipation of the district of Benjamin Constant, the city of Tabatinga became part of the newly created municipality, including it as one of the subdivisions of the main district.
A post between the borders of Tabatinga and Leticia in 1924 consistently defined the borders between Brazil and Colombia. On 4 June 1968, under Federal Law 5.449, the entire area of the municipality of Benjamin Constant, to which Tabatinga was subordinated, was classified by the Brazilian government as a National Security Area, due to its extensive open border with other countries and its poor border surveillance. For a long time Tabatinga was a district of Benjamin Constant. Tabatinga's political emancipation occurred on December 10, 1981, under the constitutional amendment of the State of Amazonas No. 12, which now defines the Tabatinga district as an autonomous municipality. The installation of municipal offices took place on January 1, 1983. The official language of the municipality is Portuguese, but Spanish and tribal languages are understood, including Tikuna language.
According to the 2022 Census by IBGE, the city is predominantly pardo, with them making up 46% of the population.
| label1 = Pardo (mixed) | value1 = 30735 | color1 = #a87b63
| label2 = White | value2 = 6569 | color2 = #f7d4cd
| label3 = Black | value3 = 1871 | color3 = #3d261a
| label4 = Yellow (Asian) | value4 = 69 | color4 = #f0d2a5
| label5 = Indigenous | value5 = 27518 | color5 = #b5925e