The Tärendö River (Swedish: Tärendö älv, Meänkieli: Täränönväylä) is a small distributary river to the Kalix River in Norrbotten, Sweden.

It is the second largest bifurcation in the world (second only to the Casiquiare canal, South America).

[2] The Tärendö River splits off the Torne River in Pajala Municipality, near the village of Junosuando, at an altitude of 210 m. It takes more than 50% of the water in the Torne River.

[2] It flows southeast for 52 km, passing Lautakoski and Koijuniemi, then empties into the Kalix River at the village of Tärendö at an altitude of 160 m. Right-bank tributaries of the Tärendö River are Meras River, Leppä River, Saitta River, and Jukkas River.

Like many other rivers in Nordkalotten and Norrland, the river is popular for fishing.