Ounasjoki
Ounajoki above the rapids
Native name	Ovnnesjohka (Northern Sami)
Location
Country	Finland
Physical characteristics
Source
• location	Ounasjärvi, Enontekiö, Finland
• elevation	450 metres (1,480 ft)
Mouth
• location	Kemijoki, Rovaniemi, Finland
Length	299.6 kilometres (186.2 mi)
Basin size	13,968 square kilometres (5,393 sq mi)

The Ounasjoki^[1] (Northern Sami: Ovnnesjohka) is the Kemijoki's largest tributary and is Finland's longest single river tributary. It is also the largest river entirely within its borders. Ounasjoki is approximately 299.6 kilometres (186.2 mi) in length, and the catchment area is 13,968 square kilometres (5,393 sq mi), 27% of the Kemijoki catchment area.

Course

The Ounasjoki originates at Ounasjärvi lake in Enontekiö. It flows first eastwards through Periläjärvi lake and turns south after some seven kilometres. The river then follows southern-southeasterly course until its confluence with the Kemijoki at Rovaniemi.

Tributaries

Left

• Näkkäläjoki
• Käkkälöjoki
• Syvä Tepastojoki
• Loukinen
• Meltausjoki

Right

• Marrasjoki

Fauna

Grayling, trout, pike and other fish typical to northern Finland are found in the Ounasjoki.^[2]