The Rio Uruçuí-Vermelho is a right-bank tributary of the Rio Parnaíba in the state of Piauí, northeastern Brazil. It originates at the Serra do Penitente in southern Piauí and flows approximately 400 kilometers through the Cerrado biome before joining the Rio Parnaíba near the town of Uruçuí. The river passes through the municipalities of Bom Jesus, Currais, and Santa Filomena along its course.

Unlike the intermittent rivers typical of the sertão, the Uruçuí-Vermelho maintains a reasonably stable flow throughout the year, fed by veredas, wetland areas, and small chapadas characteristic of the Cerrado. This perennial character makes the river accessible across seasons, though water levels are lower during the dry season when flow concentrates in deeper pools. The river carries a notable sediment load — it is responsible for the reddish, turbid coloration of the Rio Parnaíba downstream of their confluence.

The upper reaches of the river fall within the APA dos Altos Cursos dos Rios Gurguéia e Uruçuí-Vermelho, a state-administered environmental protection area of approximately 119,829 hectares established in 2017, covering municipalities including Barreiras do Piauí, Gilbués, and São Gonçalo do Gurguéia. Paddlers planning trips in this zone should consult the Secretaria do Meio Ambiente e Recursos Hídricos do Piauí (SEMARH-PI) regarding any applicable regulations.

Bom Jesus is the most practical base for accessing the river, offering lodging and services. Road access from Teresina runs via BR-343 south to Floriano and then BR-135 south to Bom Jesus, a distance of roughly 640 kilometers. Final access roads to the riverbank are typically unpaved, and a high-clearance vehicle is advisable. Wildlife in the surrounding Cerrado includes species typical of that biome, and the river supports fish including surubim, curimatã, piau, traíra, and mandi.