The Ivaí River (Portuguese, Rio Ivaí[4]) is a river of Paraná state in southern Brazil.

Its official spelling is Ivaí, with variants including Ivahy and Ival.

[5] The river basin is ecologically very degraded, with fragile and vulnerable soil.

It contains the 8,716 hectares (21,540 acres) Perobas Biological Reserve, a strictly protected conservation unit created in 2006.

This article related to a river in Paraná, Brazil is a stub.