The following table lists most rivers of Sri Lanka. Since Sri Lanka is a trilingual country, some rivers may have a Sinhala name (i.e. Kalu Ganga), while other have an English name (i.e. Kelani River). There are two words meaning "river" in the Sinhala language, namely Ganga (ගඟ) and Oya (ඔය), of which the usage of both terms is arbitrary. At 3350NaN0, the Mahaweli River is the longest river on the island, its drainage basin covering more than one-fifth of the island. It is estimated that there are 103 rivers in Sri Lanka.[1]
| Name | Length | Source | Drainage | scope=col width=80px | Image | Location of mouth | |
|---|---|---|---|---|---|---|---|
| 3350NaN0 | Horton Plains | Trincomalee | [2] | ||||
| Malvathu River | 1640NaN0 | Inamaluwa Mountains | Vankalai | ||||
| Kala Oya | 1480NaN0 | Omaragolla Mountains | Gangevadiya Wilpattu | ||||
| Kelani River | 1450NaN0 | Baththulu Oya | Colombo | ||||
| Yan Oya | 1420NaN0 | Ritigala | Pulmoddai | ||||
| Deduru Oya | 1420NaN0 | Gommuna Mountains | Chilaw | ||||
| Walawe River | 1380NaN0 | Belihul Oya | Ambalantota | ||||
| Maduru Oya | 1350NaN0 | Akurugala Mountains | Kalkudah | ||||
| Maha Oya | 1340NaN0 | Rakshawa Mountains | Kochchikade | ||||
| Kalu Ganga | 1290NaN0 | Seetha Gangula | Kalutara | ||||
| Kirindi Oya | 1170NaN0 | Namunukula | Bundala | ||||
| Kumbukkan Oya | 1160NaN0 | Lunugala | Kumana | ||||
| Menik Ganga | 1140NaN0 | Namunukula | Yala | ||||
| Gin Ganga | 1130NaN0 | Kabaragala Mountains | Gintota | ||||
| Mi Oya | 1090NaN0 | Kuda Madagala Mountains | Puttalam North | ||||
| Gal Oya | 1080NaN0 | Hewa Eliya Mountains | Oluvil | ||||
| Name | Length | Source | Drainage | Location of mouth | ||
|---|---|---|---|---|---|---|
| Attanagalu Oya | 76 km (47 mi) | Negombo Lagoon | ||||
| Nilwala Ganga | 72 km (45 mi) | Rakwana Mountains | Indian Ocean | 5°57′N 80°32′E | ||
| 700NaN0 | Semamadu Kulam | Chundikkulam Lagoon | ||||
| 700NaN0 | Horton Plains National Park | Mahaweli River | ||||
| 600NaN0 | Vavuniya District | Palk Strait | ||||
| 500NaN0 | Horton Plains | Kelani River | ||||
| 500NaN0 | Puliyankulam | Palk Strait | ||||
| 400NaN0 | Peak Wilderness Sanctuary | Kelani River | ||||
| 400NaN0 | Vavuniya District | Palk Strait | ||||
| 320NaN0 | Vavuniya District | Nanthi Lagoon | ||||
| 300NaN0 | Mullaitivu District | Palk Strait | ||||
| 270NaN0 | Pidurutalagala | Kotmale River | ||||
| 270NaN0 | Mullaitivu District | Palk Strait | ||||
| 250NaN0 | Mullaitivu District | Jaffna Lagoon | ||||
| 240NaN0 | Mullaitivu District | Chundikkulam Lagoon | ||||
| 230NaN0 | Mullaitivu District | Chundikkulam Lagoon | ||||
| 200NaN0 | Mullaitivu District | Nai Aru Lagoon | ||||
| 200NaN0 | Mullaitivu District | Chundikkulam Lagoon | ||||
| 190NaN0 | Mullaitivu District | Nanthi Lagoon | ||||
| 160NaN0 | Jaffna District | Jaffna Lagoon | ||||