| Itacaiúnas River | |
| Map Size: | 300 |
| Pushpin Map Size: | 300 |
| Subdivision Type1: | Country |
| Subdivision Name1: | Brazil |
| Subdivision Type2: | State |
| Subdivision Name2: | Pará |
| Length: | 600km (400miles) |
| Discharge1 Location: | Mouth |
| Discharge1 Avg: | 750m3/s[1] |
| Mouth: | Tocantins River |
| Mouth Coordinates: | -5.3542°N -49.1458°W |
| River System: | Tocantins basin |
| Basin Size: | 41418km2[2] |
The Itacaiúnas River is a river of Pará state in north-central Brazil.
Part of the river basin is in the Tapirapé-Aquiri National Forest, a sustainable use conservation unit created in 1989.