| Cajuapara River | |
| Source1 Location: | Maranhão state |
| Mouth: | Gurupí River |
| Subdivision Type1: | Country |
| Subdivision Name1: | Brazil |
The Cajuapara River, also known as the Açailândia River, is a river of Maranhão state in northeastern Brazil. It joins with the Itinga River to form the Gurupí River, on the border with Pará state.