The Beni River (in Spanish Río Beni) is a river in the north of Bolivia.
It rises north of La Paz and flows northeast through the pampas. One of the tributary rivers is Tuichi River in the Madidi National Park. Tuichi River joins the Beni River upstream from the town Rurrenabaque. South of Rurrenabaque, Río Beni runs through the rainforest. 30 km before joining the Mamoré River at the Bolivia-Brazil border, the rapids of Cachuela Esperanza interrupt the upstream navigability of the river.