The Río Bullileo is a river in the Nuble Region of Chile that flows westward toward the Pacific Ocean. The primary paddling run described here is the lower section, beginning just below the discharge of Embalse Bullileo dam. The put-in is located approximately 47 kilometers from Parral along a paved road, near a Carabinero station. Paddlers typically put on at the end of a soccer field about 150 meters below the dam discharge. The take-out sits above the confluence with the Río Longaví.

The run covers 9.5 kilometers with a put-in elevation of approximately 590 meters and a take-out elevation of 471 meters, yielding an average gradient of 12.72 meters per kilometer (roughly 60 feet per mile). The relevant topographic map is Bullileo F-093. GPS coordinates for the put-in are 36.31°S, 71.4°W, and for the take-out, 36.23°S, 71.49°W.

The river is noted as being best run after heavy rain, suggesting flows are variable and dependent on precipitation as well as dam releases. Other rivers in the immediate area include the Longaví, Achibueno, Perquilauquén, and Ñuble, making the region a destination for paddlers looking to combine multiple runs.

The Bullileo serves as an important water source for regional agriculture and hydroelectric generation, and the presence of the dam at Embalse Bullileo directly influences flow conditions on the lower run. The river supports diverse plant and animal life, including various fish and bird species.