The Saguenay–St. Lawrence Marine Park is a National Marine Conservation Area, one of three in the Canadian national park system, located where the Saguenay River meets the Maritime estuary of the St. Lawrence River. This park is jointly managed by Parks Canada and Sépaq. It is the first park in all of Canada to protect a purely marine environment, and covers a surface area of 1,245 km2. The area that is now the Saguenay–St. Lawrence Marine Park is a part of the Innue Essipit First Nation's land claim, and a treaty resulting from this claim could impact activities that are practiced within the park. The region surrounding the park is an important part of the history of Canada, being one of the first points of contact between Indigenous Peoples and European explorers and the birthplace of the intercontinental fur trade.

National Marine Conservation Areas (NMCAs) is a Parks Canada programme responsible for marine areas managed for sustainability and containing smaller zones of high protection. They include the seabed, the water itself and any species which occur there. They may also include wetlands, estuaries, islands and other coastal lands. They are protected from dumping, undersea mining and oil and gas exploration and development, which may damage the aquatic or terrestrial ecosystems in the conservation area. However, not all commercial activities are prohibited in these zones. Shipping, commercial and sport fishing, and recreational activities are allowed.