The Rio Iapó is a river in Paraná state, southern Brazil, flowing as a tributary of the Tibagi River. It is perhaps best known for passing through the scenic Guartelá Canyon, a protected area within the 799-hectare Guartelá State Park, established in 1992.

The primary whitewater run on the Rio Iapó is a solid day trip, predominantly class 4 with two notable class 5 rapids. Both class 5 features can be scouted or portaged on river left, though paddlers should be aware that the landing zone below the first class 5 is undercut on the left side — a significant hazard requiring careful attention. The put-in is located at approximately GPS -24.631704, -50.210583 and involves a hike of roughly a mile through farmland, downhill and then upstream to reach the river. Large rock outcroppings at the put-in are a visual highlight. The take-out is at approximately GPS -24.504276, -50.327558, accessed via a rough dirt road that may involve private property considerations.

The watershed is relatively large, which helps the river retain adequate flow well into the year, making it a viable destination across a broader seasonal window than many comparable runs. The gradient is pronounced and visible on the approach hike, and the section features abundant class 4 ledges throughout. Low-lying clouds in the canyon valley are a characteristic atmospheric feature of the area.

A commercial rafting operation, Guartelá Ecoturismo, runs a 17-kilometer section of the Rio Iapó. A fishing access point known as Cachoeira Do Meio is also located on the river.

Paddlers planning a trip should factor in the hike to the put-in and the potentially rough access road at the take-out. The undercut hazard at the first class 5 rapid warrants particular caution and thorough scouting before committing to a line.