| Ituí River | |
| Map Size: | 300 |
| Pushpin Map Size: | 300 |
| Subdivision Type1: | Country |
| Subdivision Name1: | Brazil |
| Subdivision Type2: | State |
| Subdivision Name2: | Amazonas |
| Length: | 480km (300miles)[1] to [2] |
| Discharge1 Location: | Atalaia do Norte (near mouth) |
| Discharge1 Avg: | (Period: 1970–2000)[3] (Period: 1979–2015)[4] |
| Source1 Location: | Sierra del Divisor |
| Source1 Coordinates: | -7.0847°N -72.5687°W |
| Mouth: | Javary River |
| Mouth Location: | Atalaia do Norte, Amazonas |
| Mouth Coordinates: | -4.3719°N -70.1919°W |
| Basin Size: | to [5] |
| Tributaries Left: | Rio Negro, Branquinho, Quixito |
| Tributaries Right: | Novo, Itaquai |
The Ituí River is a river of the upper Amazon Basin. It traverses some 370 km of the Atalaia do Norte municipality in the Amazonas state of north-western Brazil. The Ituí is a left tributary of the Javary River. It drains a very low gradient, dropping hardly 100 m over its whole extent, which results in extensive meandering. The Rio Negro, Beija-flor and Branquinho are some of its western tributaries, while the Rio Novo is its main eastern tributary. Downstream it joins the Itaquai River to form the upper Solimões.