The Piabanha River (Portuguese: Rio Piabanha) is a river of Rio de Janeiro state in southeastern Brazil.

The basin of the Piabanha River includes the basins of the upper Piabanha, Preto, Fagundes and Paquequer rivers.

It fully drains the municipalities of Teresópolis, Carmo, Sapucaia, Sumidouro, Areal and São José do Vale do Rio Preto, and partially drains the municipalities of Petrópolis, Paty do Alferes, Paraíba do Sul, Duas Barras and Três Rios.

[2] The Piabanha rises in Petrópolis and runs for 80 kilometres (50 mi) to join the Paraíba do Sul, passing through Areal and Três Rios.

This article related to a river in Rio de Janeiro state, Brazil is a stub.