There are hundreds of large and tiny rivers with several tributaries, many of the rivers originate in the Western Ghats ranges at high altitude. Karnataka state has 300 km of coastline where many rivers merge into the ocean. Kaveri is the longest and largest river at a length of 765 km, it originates in Talakaveri of Karnataka and merges into the ocean at (Bay of Bengal) in Tamil Nadu. The following list of rivers originates in Karnataka state. Tiny rivers are ignored from the list.
| River Name | District | Origin | Length (km) | Mouth |
|---|---|---|---|---|
| Kaveri | Coorg (Kodagu) | Talakaveri | 765 | Bay of Bengal |
| Tungabhadra | Chikmagalur | Kudali | 531 | merge to Krishna river |
| Penner | Chikkaballapura | Nandi Hills | 597 | Bay of Bengal |
| Kali | Uttara Kannada | Diggi | 184 | Arabian Sea |
| Palar | Kolar | Nandi Hills | 348 | Bay of Bengal |
| Arkavati | Chikkaballapura | Nandi Hills | 193 | merge to Kaveri River |
| Bhadra | Chikmagalur | Gangamoola | 147 | Bay of Bengal |
| Chakra | Udupi | Kundapura | - | Arabian Sea |
| Gangavalli | Dharwad | Gangavalli | 152 | Arabian Sea |
| Malaprabha | Belgaum | Soraba | 304 | merge to Krishna river |
| Kumaradhara | Dakshina Kannada | Sullia | Arabian Sea | |
| Mandovi | Belgaum | Bhimgad | 77 | Arabian Sea |
| Netravati | Chikmagalur | Gangamoola | Arabian Sea | |
| Ponnaiyar | Chikkaballapur | Nandidurg | 400 | Bay of Bengal |
| Sharavathi | Shimoga | Ambutheertha | 128 | Arabian Sea |
| Shimsha | Tumkur | Devarayanadurga | 221 | merge to Kaveri River |
| Tunga | Chikmagalur | Gangamoola | 147 | merge to Bhadra River |
| Varada | Shimoga | Vardamoola | merge to Tungabadhra |