The Kinabatangan River boasts a remarkable and diverse ecosystem, making it a haven for a wide range of wildlife in the heart of Borneo's lush rainforests. This unique ecosystem encompasses various habitats, including dense rainforests, mangrove swamps, and oxbow lakes, creating an ideal environment for a plethora of plant and animal species.

The river is particularly famous for its rich biodiversity, with an array of iconic and endangered species calling it home. Among the most notable residents are the endangered Bornean orangutans, whose treetop acrobatics can be observed along the riverbanks. The region is also home to the rare and distinctive proboscis monkeys, known for their large noses and unique social behaviors.