The Cacunduva River (Portuguese: Rio Cacunduva) is a river in the state of São Paulo, Brazil.

It is a tributary of the Una do Prelado River.

The Cacunduva River is the main tributary of the Una do Prelado River, the largest in the 84,425 hectares (208,620 acres) Juréia-Itatins Ecological Station, a strictly protected area of well-preserved Atlantic Forest created in 1986.

[1] The Una do Prelado rises in the Banhado Grande region to the south-west of the Serra da Juréia, and meanders in a north-east direction parallel to the Atlantic coast for 80 kilometres (50 mi) through a low plain between the Serra dos Itatins and the Serra da Juréia.

[2] The Cacunduva is fed by streams from the Serra dos Itatins, flows east and joins the Una do Prelado from the left (north).