The deepest river in the world is the Congo, with measured depths of around 220 m (720 ft); surveys in 2008 and 2009 found sections up to 200 m deep in its lower course between Kinshasa and Matadi. Second is the Brahmaputra, which reaches 135 m (440 ft) at Sadiya in Assam, India, and third are the Amazon in Brazil and the Orinoco in Venezuela, both with recorded depths of about 100 m (330 ft). All four figures, like the rest of this ranking, are maximum depths from the rivers' Wikipedia articles (consulted October 2026). Two things separate this from other river rankings: the figure is a single deepest point, not an average, and it measures water, not the height of the canyon walls around it. Most of the ten rivers below are only a few metres deep for most of their length.
What "deepest river" actually measures, and why sources disagree
Depth is the hardest of the three river superlatives to pin down. Length and width can be read from maps and satellite images; depth has to be measured from a boat, and the deepest spots are usually in the fastest, most dangerous water. So the numbers come from a patchwork of surveys made in different decades with different instruments, and the ranking below should be read with that in mind.
Maximum depth, not average depth
Every figure in this ranking is the deepest single point recorded. A river's average is far lower. The Yenisei reaches 61 m but averages 14 m. The Mississippi is about 0.9 m deep where it leaves Lake Itasca, 2.7–3.7 m between Saint Paul and St. Louis, and only reaches 61 m at New Orleans. The Brahmaputra averages 30 m against its maximum of 135 m. A deep point usually forms where a large flow is squeezed through a narrow gap or scours the outside of a tight bend.
Water depth, not canyon depth
Lists of "deep rivers" often mix in canyon figures. The Indus passes through a gorge 4,500–5,200 m deep near Nanga Parbat, the Salween cuts canyons up to 4,500 m deep in Yunnan, and the Yarlung Tsangpo Grand Canyon, on the upper Brahmaputra, averages about 5,000 m deep around Namcha Barwa and reaches 6,009 m at its deepest. Those numbers measure rock above the river, not water below the surface, and this ranking leaves them out.
Rivers, not fjords or reservoirs
The Saguenay Fjord in Quebec averages 210 m and reaches 270 m, deeper than any point on the Congo, but it is a drowned glacial valley filled by sea water, so it is treated as an arm of the sea. Reservoirs behind dams are also excluded, since their depth is set by engineers.
Depth that changes with the season and with dredging
Depth moves with the flow. The Orinoco's 100 m is a rainy-season figure, when the river also swells to 22 km across. People change depth as well: the Hudson below the Federal Dam at Troy is dredged to keep a 9.1 m shipping channel, and dams turn whole gorges into reservoirs, as the Iron Gate I dam did to the Danube in 1972. A depth measured in one year is not guaranteed in the next.
The ten deepest rivers, from the Congo to the Mackenzie
With those rules applied, the ranking is as follows. Where two rivers share a figure they share a rank. Some depths that circulate widely online, such as a maximum of around 200 m for the Yangtze or 178 m for the Danube, do not appear in those rivers' Wikipedia articles, and because they cannot be traced to a survey they are left out here. If a better-documented measurement appears, the order below could change.
| Rank | River | Country (deepest point) | Maximum depth |
|---|---|---|---|
| 1 | Congo | DR Congo (lower course) | about 220 m |
| 2 | Brahmaputra | India (Sadiya, Assam) | 135 m |
| 3= | Amazon | Brazil (lowermost section) | up to 100 m |
| 3= | Orinoco | Venezuela (rainy season) | up to 100 m |
| 5 | Danube | Serbia and Romania (Gospođin Vir, Iron Gates) | 82 m |
| 6 | Hudson | United States (World's End, West Point) | 62 m |
| 7= | Yenisei | Russia | 61 m |
| 7= | Mississippi | United States (New Orleans) | 61 m |
| 9 | St. Lawrence | Canada (Quebec City) | 60 m |
| 10 | Mackenzie | Canada (The Ramparts) | 45 m |
The Congo below Kinshasa: up to 200 m deep in a channel under 800 m wide
The Congo's depth is the product of two extremes meeting. It is the third-largest river in the world by discharge, at about 41,000 m³/s, and because its basin straddles the equator its flow stays steady through the year. Yet below Pool Malebo, where Kinshasa and Brazzaville face each other, that water is forced into a gorge. Through the Livingstone Falls, a chain of rapids that drops 270 m over 350 km to Matadi, the channel is under 800 m wide for most of its length and less than 300 m wide in places.
Pushing that volume through so narrow a gap scours the bed far below the level of the banks. Investigations in 2008 and 2009 found that sections between the rapids may be as deep as 200 m, and the river's Wikipedia article gives measured depths of around 220 m. That makes the Congo the deepest river ever recorded.
The depth has biological consequences. The rapids isolate fish populations, so new species have evolved close to one another, and the Livingstone Falls stretch alone holds more than 300 fish species, about 80 of them found nowhere else. One of them, the blind, unpigmented cichlid Lamprologus lethops, is thought to live as deep as 160 m. The same drop is the reason for the Inga dams, about 200 km southwest of Kinshasa, where Inga I and Inga II generate 1,776 MW. More on the river's basin and history is in our guide to the Congo River.
From Sadiya to the Ramparts: how the other nine got deep
2. Brahmaputra, 135 m, India
The Brahmaputra is deepest at Sadiya in eastern Assam, soon after it leaves the Himalayan gorges where Tibet's Yarlung Tsangpo becomes the Siang and then the Brahmaputra. Its floods reach about 103,000 m³/s when Himalayan snow melts in spring, and that energy carves the bed. Downstream on the plains of Assam and Bangladesh the same river spreads up to 20 km wide and is far shallower. The Brahmaputra basin spans China, India, Bhutan and Bangladesh.
3=. Amazon and Orinoco, 100 m, Brazil and Venezuela
The Amazon carries more water than any other river, about 215,000–230,000 m³/s, but most of it spreads sideways rather than down. Between Manacapuru and Óbidos it is 20–26 m deep, and in its lowermost section it averages 20–50 m, reaching 100 m in places. The Orinoco reaches the same 100 m only in the rainy season, when its basin, two-thirds of it in Venezuela, receives about 2,300 mm of rain a year.
5. Danube, 82 m, Serbia and Romania
The Danube is deepest in the Iron Gates, or Đerdap, gorge on the Serbia–Romania border, where it cuts between the southern Carpathians and the foothills of the Balkan Mountains. The Đerdap National Park article records a depth of 82 m in Gospođin Vir, a 15 km gorge that narrows to 220 m, and describes it as one of the greatest river depths measured anywhere. Farther downstream, in the Great Kazan, the river squeezes to about 150 m wide and reaches 53 m, the figure many lists use instead. Since 1972 the Iron Gate I dam has held the river back as Lake Đerdap, so these depths should be read with the same caution as any in a dammed stretch. The gorge is protected as Đerdap National Park in Serbia and the Iron Gates Natural Park in Romania.
6. Hudson, 62 m, United States
The Hudson's deepest point, known as World's End, lies between Gee's Point at the US Military Academy at West Point and Constitution Island, just before the river enters the Hudson Highlands between Orange and Putnam counties, New York. It is 202 ft (62 m) deep, while the shipping channel farther south is dredged to only about 9 m. The lower Hudson is a tidal estuary as far north as Troy, with two high tides a day.
7=. Yenisei and Mississippi, 61 m, Russia and the United States
The Yenisei, the largest river flowing to the Arctic Ocean, reaches 61 m but averages only 14 m. Its system also takes in Lake Baikal, the deepest lake on Earth, whose outflow, the Angara, joins the Yenisei near Strelka in Krasnoyarsk Krai. The Mississippi's 61 m (200 ft) is in New Orleans, near the end of its course, after the Missouri and the Ohio have both joined it. Between St. Louis and Cairo, Illinois, it averages about 9 m, and below Cairo 15–30 m.
9. St. Lawrence, 60 m, Canada
In its fluvial estuary, the stretch below Lake Saint-Pierre where the river is still under the power of freshwater tides, the St. Lawrence's main channel is mostly 13–40 m deep, with a pool of 60 m at Quebec City. Downstream, the maritime estuary toward Pointe-des-Monts is among the deepest estuaries in the world, but it is sea water and falls outside a river ranking.
10. Mackenzie, 45 m, Canada
The Mackenzie, which with the Slave, Peace and Finlay forms Canada's longest river system, reaches 45 m at The Ramparts, a limestone gorge in the Northwest Territories barely 500 m wide, below the Mountain River on its way north to the Beaufort Sea.
The common thread is the Congo's lesson repeated at smaller scale: a large river forced through a narrow gorge or a tight bend digs deep, while the same river on an open plain spreads out and stays shallow. Depth is the least studied of the river records, and the rivers that lead it are mostly not the ones that top the list of the longest rivers in the world.