The Paraná River (, ) is a river in south Central South America, running through Brazil, Paraguay, and Argentina for some . It is second in length only to the Amazon River among South American rivers. The name Paraná is an abbreviation of the phrase "para rehe onáva", which comes from the Tupi language and means "like the sea" (that is, "as big as the sea"). It merges first with the Paraguay River and then farther downstream with the Uruguay River to form the Río de la Plata and empties into the Atlantic Ocean.

This article refers to the river in Goiás, central Brazil: for the longer river of southern Brazil, Argentina and Paraguay, see Paraná River. The difference between the two is in the diacritic on the final syllable.

The Paranã River is located in Goiás state, Brazil. It divides two regions - the Northeast and north-central Goiás. It is formed by tributaries that descend the Serra Geral, the mountains that divide eastern Goiás and Bahia. One of the most important tributaries is the Crixás, which has its source near Formosa. Farther to the north the Paranã becomes the main tributary of the Tocantins River on the right bank. Today it is crossed by a long concrete bridge between the municipalities of Iaciara and Nova Roma. It forms the valley which makes up a vast region called the Vão do Paranã Microregion.