thumb|250px|Salmon fishing on the Cascapédia River, by [[Albert Bierstadt, 2nd half 19th century.]]
The Cascapédia River is a river in the Gaspé Peninsula of Quebec, Canada, which has its source at Lake Cascapedia, fed by streams of the Chic-Choc Mountains, and empties into Cascapedia Bay (Baie de la Cascapédia), a small bay of Chaleur Bay. The river is about long. At times, it is also called Grand Cascapédia River to differentiate it from the Little Cascapédia River which empties into the same bay just to the east.
The Cascapedia is known for its Atlantic salmon (salmo salar) fishing. With average catches of and a record catch of , caught in 1886, the river has long been recognized as one of Quebec's richest salmon rivers. Already back in 1835, surveyor Joseph Hamel noted the abundance of fish, including trout, salmon, carp, and whitefish. Several Governors General of Canada, including The Marquess of Lansdowne and Lord Stanley, had summer homes along this river.
Geography
The Cascapédia River is entirely undammed and wild, and no municipality is using it for its wastewater. Because its source is the Chic Choc Mountains that are largely made up of soluble limestone, its waters are rich in carbonates and low in sulfates and chlorides, with a higher conductivity and pH level than typical water of the Canadian Shield. The lack of agriculture and industry keep the river free from pollution. Its water is rated of the highest quality.