The 9 Longest Rivers in the World: From the Nile to the Congo

Rivers act as natural collectors of water. As freshwater moves across the land, gravity pulls it toward the lowest points, where it merges with other water molecules. This accumulation starts as a tiny trickle, which combines with others to form small streams. These streams then converge into larger waterways, eventually becoming full-fledged rivers.

A watershed refers to the land area that channels all water within a specific region to a single outlet, typically where a river meets the sea. Watersheds vary in size, influenced by the terrain, and some can be enormous. Larger watersheds often give rise to massive rivers.

Determining where a river begins, as opposed to where smaller creeks and streams converge, is a challenging task. To rank rivers by length, a starting point must be established, often requiring some arbitrary decisions for measurement purposes. According to the U.S. Geological Survey, "the length of a river can be measured from its mouth to the farthest headwater source (regardless of the stream's name) or to the headwaters of the stream typically identified as the source stream."

Presented here, from the Nile to the Congo, are the world's nine longest rivers:

1. The Nile River

The title of the world's longest river is a matter of debate. Is it the Nile in Africa or the Amazon in South America? While both are similar in length, a 2009 study published in the International Journal of Digital Earth concluded that the Nile is slightly longer at 4,132 miles (6,650 kilometers). The Guinness World Records also recognizes the Nile as the longest river globally. The Nile is fed by two main tributaries — the White Nile and the Blue Nile — which converge in Khartoum, Sudan's capital. The river drains a vast area of 1,293,056 square miles (3,349,000 square kilometers) across Sudan, Ethiopia, Egypt, Uganda, Tanzania, Kenya, Rwanda, Burundi, Eritrea, and the Democratic Republic of the Congo, eventually flowing into the Mediterranean Sea.

2. The Amazon River

The Amazon River traverses Peru, Colombia, and Brazil. While the Nile is officially recognized as the world's longest river, many argue that the Amazon holds this title. Undoubtedly, it is the largest river by volume, discharging more freshwater into the Atlantic Ocean daily than the next seven largest rivers combined. Its largest drainage area spans 2,400,000 square miles (6,300,000 square kilometers), covering nearly 40% of South America. However, most researchers agree that the Amazon is approximately 4,000 miles (6,500 kilometers) long, slightly shorter than the Nile's 4,132 miles (6,650 kilometers).

3. The Yangtze River

Asia is home to many of the world's longest rivers, with the Yangtze being the longest among them. Stretching 3,900 miles (6,300 kilometers), it rivals the Nile and Amazon in length. It is also the longest river to flow entirely within one country, draining a fifth of China's land area, which constitutes 6.3% of the world's landmass. The Yangtze boasts over 700 tributaries and a watershed of 698,265 square miles (1,808,500 square kilometers), supporting a third of China's population.

4. The Missouri River

The longest river in North America and the world's fourth-longest river, the Missouri River, originates in the Rocky Mountains of the U.S. and drains 500,000 square miles (1,300,000 square kilometers), including parts of two Canadian provinces. Stretching 2,341 miles (3,767 kilometers), the Missouri joins the Mississippi River — America's second-longest river, slightly shorter than the Missouri — near St. Louis, Missouri. Together, their waters flow into the Gulf of Mexico, forming a river system that drains 32 U.S. states.

5. The Yenisey River

The Yenisey River in Siberia, spanning 2,167 miles (3,487 kilometers), flows into the Arctic Ocean and is fed by Lake Baikal, the world's deepest and oldest lake, renowned for its clarity. The Selenga River, originating in northern Mongolia, travels 616 miles (992 kilometers) into Lake Baikal, which then feeds the Angara River. The Angara becomes the Yenisey, forming the Yenisey-Angara-Selenga river system, the fifth longest globally, at 3,442 miles (5,539 kilometers).

6. The Yellow River

China's Yellow River, known as the Huang He, stretches 3,395 miles (5,464 kilometers). Originating in the Bayan Har Mountains of central China, it flows eastward through nine provinces before emptying into the Bohai Sea. With a drainage area of 307,000 square miles (795,000 square kilometers), it is widely regarded as the cradle of ancient Chinese civilization, supported by extensive archaeological evidence.

7. The Ob-Irtysh River

The Ob-Irtysh river system ranks as the seventh-longest in the world. The Ob River begins in the Altai Mountains of western Siberia, while the Irtysh River starts in Mongolia, flowing through China and Kazakhstan before reaching Russia. Combined, these rivers span 3,360 miles (5,410 kilometers) and drain an area of 1,154,445 square miles (2,990,000 square kilometers).

8. The Rio de la Plata-Paraná-Rio Grande Rivers

The Rio Grande, which flows into the Paraná River and eventually into the Rio de la Plata, reaching the Atlantic Ocean at the border of Uruguay and Argentina, is the world's eighth-longest river and South America's second-longest river system. Spanning 3,032 miles (4,880 kilometers), it drains an area of 997,175 square miles (2,582,672 square kilometers) across Brazil, Argentina, Paraguay, Bolivia, and Uruguay.

9. The Congo River

The Congo River, located in west-central Africa, ranks as the ninth longest river globally and the second longest on the African continent. Its shape resembles a tree with numerous branches, and its farthest headwater, the Chambeshi River, originates in Zambia's mountains. Stretching 2,920 miles (4,700 kilometers), the Congo river system drains an area of 1,550,000 square miles (4,014,500 square kilometers) and boasts the world's second-largest river discharge.