| Muonio | |
| Name Native: | |
| Subdivision Type1: | Countries |
| Subdivision Type3: | County |
| Length: | 387km (240miles)[1] |
| Discharge1 Avg: | 165m3/s |
| Source1: | Confluence of Könkämäeno and Lätäseno |
| Source1 Coordinates: | 68.4844°N 22.2958°W |
| Mouth: | Torne River |
| Mouth Coordinates: | 67.1808°N 23.5583°W |
| Basin Size: | 14430km2 |
The Muonio (Finnish: Muonionjoki or Kätkäsuvanto; Swedish: Muonio älv or Muonioälven in Swedish pronounced as /mʉˈǒːnɪɔ ˈɛlːv/;[2] Muonionväylä) is a river in northern Finland and Sweden. It is a tributary of the Tornio. Together the two rivers form the national border between Finland and Sweden. The river is 230 kilometres long.