As one of the largest and most diverse continents on earth, South America has an abundance of rivers and waterways. It is home to several remarkable features, including Angel Falls, the Amazon River (the world’s longest river), the Amazon Rainforest, the Atacama Desert, and the Andes mountain range. However, there are a few that cover vast stretches of land. From the world-famous Amazon River to the lesser-known Purús River, let’s delve into the top 10 longest rivers in South America.
The Longest Rivers in South America Ranked in Ascending Order
10. Orinoco River
Length: 2150km or 1340miles
Runs Through: Colombia, Venezuela, South America
The Orinoco river is one of the longest rivers in South America. It is a 2150 km long river passing through Colombia, Venezuela and South America.
The Orinoco River and its tributaries serve as the primary transportation network for eastern and interior Venezuela and the Llanos region of Colombia as it is one of the the longest rivers in South America. The Orinoco basin boasts an incredibly diverse environment and wildlife. The Orinoco River’s drainage basin, often referred to as the Orinoquia, spans approximately 1 million km², with about 65% located in Venezuela and 35% in Colombia.
Originating high in the Sierra Parima Mountains of Venezuela and Brazil, the Orinoco River traverses through dense rainforests, flooded forests, expansive grasslands, and a broad delta before reaching the Atlantic Ocean. This river is home to the critically endangered Orinoco crocodile, river dolphins, giant river otters, the giant anaconda, and over 1,000 fish species. Additionally, it serves as a haven for diverse birdlife, including flamingos, vibrant parrots, and the scarlet ibis.
9. Rio Negro River
Length: 2250km or 1398 miles
Runs Through: Colombia, Venezuela, Brazil
The Rio Negro is one of the longest rivers in South America. It is a 2250 km long river passing through Brazil, Colombia, Venezuela.
The Rio Negro drains three main areas: northern tributaries originating in the southern Guiana Shield, western headwaters originating in the Colombian Andes, and right-bank tributaries originating in the lowlands.
The Rio Negro, also known as the largest blackwater river in the world, contributes about 14% of the average annual discharge into the Amazon, making it second only to the Madeira River. In contrast, its main tributary, the Rio Branco, is a whitewater river. While it is not as turbid as the Amazon or Madeira, it becomes muddy during the flood season.
The Rio Negro basin hosts over 90 endemic species, including the unique Denticetopsis sauli from the lower Pamoni River in the Cassiquiare Canal area, and six monotypic genera found exclusively in this basin. More than 100 species are popular in the aquarium trade, such as the iridescent cardinal tetra (Paracheirodon axelrodi), which may have adapted its coloration to the blackwater environment.
Ecological phenomena include large migrations of doradid catfishes, characids like Brycon, and prochilodontids of the genus Semaprochilodus; for example, the jaraqui (Semaprochilodus insignis) migrates from blackwater to whitewater rivers to spawn. The basin also features unique species assemblages on leaf-litter deposits and numerous miniaturized forms.
8. Tocantins
Length: 2640 km or 1640 miles
Runs Through: Brazil
The Tocantins River is one of the longest rivers in South America. It is also known as ‘toucan’s beak’ and flows through Goiás, Tocantins, Maranhão, and Pará. Unlike many of the South American rivers, the Tocantins ends its course in the Atlantic Ocean rather than into the Amazon River. The main tributaries of the Tocantins River are the Paranã River, Sono River, Araguaia River, and the Itacaiúnas River.
The Tocantins is home to many interesting animal species, such as the Amazonian Manatee and Araguaian River Dolphin. Reptiles like the Black Caiman and Yellow-Spotted River Turtle also call the river home.
7. Paraguay River
Length: 2695km or 1674 miles
Runs Through: Brazil, Bolivia, Paraguay and Argentina
The Paraguay River is one of the longest rivers in South America. It flows approximately 2695km from Mato Grasso to Corrientes. It flows through Brazil, Bolivia, Paraguay and Argentina. The major tributaries of the river are Tebicuary, Ypané, Manduviré, Aquidabán, Apa, Confuso, Verde and Montelindo.
Paraguay’s rich biodiversity includes 395 fish species, 88 amphibians, 135 reptiles, and 688 bird species, including Crowned Solitary Eagle (Endangered) and Bare-faced Curassow (Vulnerable). The 181 mammal species recorded include the threatened Chacoan Peccary (Endangered)—thought extinct until the first live individuals were sighted in 1970—as well as Lowland Tapir, Marsh Deer and Southern Tiger Cat (Vulnerable), and nine species of armadillos, including the rare Giant Armadillo (Vulnerable).
6. Japurá River
Length: 2820km or 1752 miles
Runs Through: Columbia and Brazil
The Japurá River, stretching 2,820 kilometers (1,750 miles), is located in the Amazon basin and is the 6th longest river in South America.
Originating in Colombia, it flows eastward through Brazil before merging with the Amazon River. Some tributaries of the Japurá River originate very close to the Solimões River (Auati Paraná River), and some tributaries of the Negro River arise near the Japurá (Uneiuxi, Cuiuni, and Unini rivers), with connections and bifurcations between them during flood seasons. It has a basin size of 276,812 km2 (106,878 sq mi).
The rivers hold a range of fish, turtles, the Amazon river dolphin, and the Amazonian manatee. Prevalent birds are species of macaw, heron, tinamou, and parrot. The Japurá-Solimões Moist Forests ecoregion is mostly intact, especially in the interior.
5. São Francisco River
Length: 2914km or 1810 miles
Runs Through: Columbia and Brazil
The São Francisco River is the fifth longest river in South America. It is located entirely in eastern Brazil, and it also the longest river in the country.
Originating in the Canastra Mountains, it spans approximately 2914km traversing five states before emptying into the Atlantic Ocean. The climate within its 641,000 km2 (247,000square-mile) basin is among the driest in Brazil. The river receives water from 168 rivers and streams, with 90 located on its right bank and 78 on its left bank. The main tributaries include the Paraopeba River, Abaeté River, Das Velhas River, Jequitaí River, Paracatu River, Urucuia River, Verde Grande River, Carinhanha River, Corrente River, and Grande River.
The São Francisco basin features diverse plant and animal life across its regions. In the upper basin, savannas and mixed forests are home to hardwoods like jacaranda and Brazilian cedar, along with cochineal cactus and vanilla plants. The middle basin’s caatinga vegetation includes thorny trees such as catingueiras and juremas, while the sertão region supports xerophytic plants like carnauba palms and cacti. The lower river, a floodplain, originally supported tropical semi-deciduous forests, though much has been cleared for agriculture. Animal life includes marsupials, rodents like capybara, skunks, and the titi monkey. Bird species such as tinamous, parrots, and hummingbirds are found here, while fish include robalo, sardines, and pocomó. The river mouth also hosts manatees and sharks.
4. Juruá River
Length: 3283km or 2040 miles
Runs Through: Brazil and Peru
The Juruá River is the fourth longest rivers in South America. It is located Brazil and passes through Peru.
For most of its course, the river traverses the Purus várzea ecoregion, which is encircled by the Juruá-Purus moist forests ecoregion. Originating in the Ucayali highlands, the river is navigable and free of obstructions for 1,133 km (704 mi) above its confluence with the Amazon. Spanning approximately 3,283 km (2,040 mi) in total length, it ranks among the longest tributaries of the Amazon. It has a drainage basin of 190,573 km2.
The sandy beaches along the Juruá River are crucial for the reproduction of several threatened or overexploited species, including the giant South American river turtle (Podocnemis expansa), yellow-spotted river turtle (Podocnemis unifilis), and six-tubercled Amazon river turtle (Podocnemis sextuberculata). These riverine beaches also serve as breeding grounds for the Orinoco goose (Neochen jubata), black skimmer (Rynchops niger), large-billed tern (Phaetusa simplex), and various migratory species such as sandpipers and ospreys (Pandion haliaetus), among other specialty species. This area is a priority in the Amazon for many resident and migratory bird species.
The numerous oxbow lakes provide essential habitats for fish reproduction, especially the pirarucú (Arapaima gigas), and serve as feeding sites for turtle hatchlings and waterbirds.
3. Purus River
Length: 3382 km or 2101 miles
Runs Through: Brazil and Peru
The Purús River is one of the longest rivers in South America. The Purús River is a biodiverse waterway between Peru and Brazil and flows through South America for a whopping 3382 km or 2101 miles. The source of the river is located in the Ucayali Region in Peru, and, as a tributary river, it ends its course at the larger Amazon River. The Purús has a sizeable drainage basin of 371,042 km2.
There are many animals that live in this longest rivers in South America and around the Purús. However, one mammal is particularly unique. The Purús Red Howler is a monkey that is native to the Bolivian, Brazilian, and Peruvian regions.
2. Paraná River (a.k.a Río de la Plata)
Length: 4880 km or 3030 miles
Runs Through: Brazil, Argentina, Uruguay, Paraguay, and Bolivia
Rio de la Plata or Parana River is one of the longest rivers in South America. In Spanish, Rio de la Plata means River of Silver but is more commonly known as River Plate. It covers 4880 km across South America and runs through Brazil, Argentina, Uruguay, Paraguay, and Bolivia before eventually emptying into the Atlantic Ocean.
The Río de la Plata is the estuary formed by the confluence of the Uruguay River and the Paraná River at Punta Gorda. There are some well-known capital cities that rely on the river, such as Buenos Aires and Montevideo. With a large drainage basin of 3,170,000 km², many source rivers flow into la Plata. These connecting water bodies include the Paranà River, the Paraguay River, and the Uruguay River.
The Rio de la Plata as a longest rivers in South America has a wide variety of animals living in its waters. The Loggerhead Sea Turtle, Leatherback Sea Turtle, and the endangered La Plata Dolphin all can be found within the river. There was a lot of historical significance with multiple battles that took place throughout the years. Important battles noted was the Battle of Juncal in 1827 and the Battle of the River Plate in 1939.
1. Amazon River: The Longest River in South America
Length: 6400 km or 3976 miles
Runs Through: Brazil, Peru, Colombia, Ecuador, Bolivia, and Venezuela
At 6400 km, the Amazon River is by far the longest rivers in South America alongside being the second largest river in the world. The Amazon River has a monumental drainage basin, at 7,000,000 km². It is known that just the Brazilian section of the basin is larger than any other around the world. The Nevada Mismi Peak is regarded as the source of the river, located southeast of Lima. The Amazon subsequently flows through Brazil, Peru, Colombia, Ecuador, Bolivia, and Venezuela, emptying into the Atlantic Ocean.
One of the most exciting aspects of the Amazon River is the unique animals within the ecosystem. The Amazon River being the longest rivers in South America is a home to Dolphin, Amazonian Manatee, and Giant Otter. Anacondas and Caimans also live in the waters of the Amazon alongside many fish species, such as the Piranha, Arapaima, Electric Eel, and occasionally the Bull Shark.
Ocean Insights: Hear From Our Experts
By Rida Nasir
Researcher and Conservationist, with an MSc in Environmental Science
Rivers like the Amazon, Paraná, and Orinoco are not just bodies of water; they are lifelines for vast ecosystems. By detailing the flora and fauna supported by these rivers, the article raises awareness about biodiversity and the need for conservation. This awareness is crucial in an era where environmental degradation and climate change threaten these delicate ecosystems. Moreover, The Amazon River, spanning approximately 6,400 km across equatorial South America, forms by far the largest river system. It carries more water than any other river, accounting for one-fifth of the world's total flowing fresh water. Culturally, South America's longest rivers have played pivotal roles in shaping the histories and lives of the people living along their banks. Economically, rivers are crucial. These rivers provide us with economic activities like agriculture, fishing, transportation, and hydroelectric power. Understanding the economic impact of these rivers provide us with a broader perspective on their importance to national and regional economies.
FAQs
Is the Amazon River the longest river in the world?
It is largely debated that the longest river in the world is either the Amazon River or the Nile River. It all depends on what measurements you go by. The widely accepted notion is that the Amazon is noted as 6400 km, while the Nile is recorded at 6650 km.
What are the two longest rivers in Latin America?
The two longest rivers in Latin America are the Amazon River (6400km/3976 miles) and the Rio de la Plata (4880km/3030 miles).
