Rio de Janeiro is home to approximately 6.7 million people, however, when considering the Greater Rio de Janeiro metropolitan area, which includes surrounding municipalities, the population rises to about 13.5 million people - making it the second-largest metropolitan area in Brazil, after São Paulo. It is the 4th largest city in South America. São Paulo is in first place with 12.4 million inhabitants, followed by Lima (Peru) in second place with 10 million, and Bogotá (Colombia) in third, with 8 million.

Background of Rio de Janeiro

Rio de Janeiro began as a region inhabited by the Tupi people, and was first encountered by Portuguese explorers in January 1502, who mistook Guanabara Bay for the mouth of a river - hence the name 'Rio de Janeiro' or 'January River'. The Portuguese established a permanent settlement in 1565 to defend the area from French attacks and native resistance.

By the 18th century, Rio had grown significantly due to its role in the export of gold and coffee, and in 1763, it became the capital of colonial Brazil, replacing Salvador. The city's status elevated further in 1808, when the Portuguese royal family fled Napoleon’s invasion of Portugal and made Rio their seat of power - making it the only European capital ever located outside Europe.

In 1822, Brazil declared independence, and Rio remained the capital of the newly formed empire, continuing as the political and economic heart of the nation. The city flourished during this time, becoming a hub for trade, governance, and culture.

Even after Brazil became a republic in 1889, Rio de Janeiro retained its position as national capital until 1960, when it was replaced by Brasília, a purpose-built city in the interior. Despite losing political status, Rio remained a symbol of national identity, known worldwide for its beaches, the carnival, and iconic landmarks like Christ the Redeemer.

Brasília, a new capital city

Rio de Janeiro remained the capital city until 1960 when it was replaced by Brasilia (pictured below), which was seen as a better choice than Rio for a number of reasons...

Central location for national unity - Brasília is located in the interior of Brazil, more central than Rio. This helped reduce the coastal bias and aimed to integrate the entire country more fairly, and symbolised unity and accessibility for all regions - north, south, east, and west.

It would stimulate interior development - much of Brazil's population and infrastructure were concentrated along the coast, and the government wanted to promote growth and settlement in the inland areas, especially the underdeveloped central and western regions.

There were urban problems in Rio - by the mid-20th century, Rio suffered from overcrowding, traffic congestion, housing shortages, and limited space for expansion, so moving the capital allowed for more controlled urban planning in a new environment.

It was a vision of modernisation - Brasília was designed by renowned architect Oscar Niemeyer and urban planner Lúcio Costa to be a modern, planned city - it represented Brazil’s aspirations for modernisation, innovation, and a break from colonial traditions.

Political neutrality - Rio, as a major economic and cultural hub, was also politically influential, whereas Brasília offered a fresh start, free from the strong regional influences of existing major cities like Rio or São Paulo.

How has Rio de Janeiro grown?

1960s: At the time Rio was still Brazil's capital (until Brasília took over in 1960), and urban development was concentrated around the city centre (Centro) and nearby southern zones like Copacabana and Botafogo. These areas housed the main economic and political institutions, and were well connected by roads and early public transport, drawing people to live and work nearby.

1990s: As Rio’s population grew, the city expanded into the northern suburbs and along key road corridors. Favelas (informal settlements) spread across hillsides and less accessible urban edges, particularly near job-rich zones. Areas like Barra da Tijuca in the west began developing as new residential and commercial hubs, supported by road expansion and improved infrastructure.

2010s onwards: Urban sprawl accelerated both westward into Recreio and Campo Grande, and northward along transport axes. The Olympic Games (2016) brought new investment and infrastructure, especially in the Barra region. Meanwhile, the eastern and coastal areas remained dense and economically significant, while socio-spatial divisions widened between affluent neighbourhoods and expanding informal areas.

Population growth in Rio de Janeiro

Despite no longer being Brazil’s capital, Rio de Janeiro remains one of the country's most important cities - economically, culturally, and symbolically. As a result, it continues to experience significant population growth, with the Greater Rio area estimated to house over 13.5 million people. Although growth has slowed compared to earlier decades, Rio remains a major destination for internal migration and a magnet for economic activity and tourism...

• Natural increase – while not as high as in previous decades, Rio still experiences natural population growth, with births exceeding deaths, particularly in lower-income areas
• Migration – people from rural areas and smaller towns in Brazil continue to migrate to Rio in search of jobs, education, and better services, especially from northern and north-eastern regions of the country
• Economic importance – Rio is a major centre for finance, oil and gas, tourism, media, and entertainment, so it attracts workers across many sectors, both formal and informal
• Historical factors – Rio’s historic role as the capital of Brazil established its urban, political, and economic infrastructure early, and the offshore oil boom in the late 20th century further boosted its economy and spurred investment, especially in the energy sector

Population growth in the city of Rio by decade:

• 1990 = 5.5 million inhabitants
• 2000 = 5.6 million inhabitants
• 2010 = 6.2 million inhabitants
• 2020 = 6.7 million inhabitants

You can see this growth in more detail on the graph below...

NB: Rio's growth is somewhat limited by its physical geography - surrounded by the ocean and mountains on all sides.

The population today

Rio de Janeiro covers a land surface area of approximately 1,200 sq m and is home to around 6.7 million people in the city, with over 13.5 million in the wider metropolitan area. This gives Rio a population density of about 5,200 people per sq km, making it one of the most densely populated cities in Brazil. High-density urban living is clearly visible, especially in favelas (informal settlements - seen in the image below) built on hillsides and marginal land. Roughly 20–25% of Rio's residents live in these informal settlements, where poverty, limited access to services, and housing insecurity are widespread.

Rio is a diverse and multicultural city, shaped by centuries of migration and colonial history. The population includes people of European (particularly Portuguese), African and indigenous descent, as well as more recent immigrant communities. A large proportion of Rio’s population is of Afro-Brazilian heritage, a legacy of the transatlantic slave trade, which brought millions of enslaved Africans to Brazil - more than to any other country in the Americas.

Brazil is a majority Christian country, and in Rio around 65–70% of residents identify as Roman Catholic, while a growing number belong to Evangelical Protestant churches. Religious life in the city is also influenced by Afro-Brazilian spiritual traditions like Candomblé and Umbanda, which blend African, indigenous, and Catholic beliefs.