Rio dos Bois is a Cerrado-sourced river flowing through the northwest region of Goiás, Brazil. As an important tributary of the headwaters of the Araguaia River, it forms part of the broader Araguaia-Tocantins basin — one of South America's most ecologically significant river systems. The river winds through a classic Cerrado mosaic landscape, and its waters support a rich and diverse ichthyofauna that reflects both the biological richness of the Cerrado biome and the river's role as a natural nursery for numerous fish species. The Rio dos Bois is notable not only for its angling potential but also for its ecological importance, harboring endemic species found nowhere else on Earth.