The Bonnechère River is a river in eastern Ontario, Canada. It starts in Algonquin Park and flows southeasterly through Renfrew County, emptying into the Ottawa River east and north of Renfrew, Ontario. The river is 145 km in length and drains an area of 2,400 km².

During the 1800s, the river was used to transport white pine logs from the forested areas surrounding the river. A number of hydroelectric plants have been built on the river.

The Bonnechère Caves, formed from ancient limestone, are located by the river near the village of Eganville, Ontario , in the hamlet of Fourth Chute, Ontario.

The First Chute (waterfall) of the river is where the Bonnechere empties into the Ottawa River. The Second Chute is in Renfrew, this waterfall has a small hydroelectric dam. The Third Chute is in Douglas, Ontario, it also has a small hydroelectric dam. The Fourth Chute is in the small village Fourth Chute, and the Fifth Chute is in Eganville, Ontario .

Tributaries of this river include the:

• Aylen River
• Pine River
• Sherwood River

The river flows through Golden and Round Lakes . Bonnechere Provincial Park is located on Round Lake.

The river's name is thought to come from the French "bonne chère" meaning "good eating", which suggests that early explorers found an ample supply of game animals in this region.