Desolation Sound Marine Provincial Park, Marine provincial park in British Columbia, Canada

Desolation Sound Marine Provincial Park covers about 84 km2 of water, small islands and mainland shore at the meeting of Malaspina Inlet and Homfray Channel, 32 km north of Powell River. Its steep forested slopes, glaciated peaks and waterfalls drop into the sea, and the sheltered coves and anchorages draw yachts each summer. It is British Columbia's second-largest marine provincial park after Broughton Archipelago.

George Vancouver sailed into the sound in 1792 and named it Desolation Sound, seeing abandoned settlements, gloomy weather and barren land. His visit likely followed a smallpox outbreak, came in the season when people were inland hunting and gathering, and coincided with Lekwiltok raids. From 1875 the Sliammon (Tla'amin) were pushed onto small reserves, and in 1920 legislation allowed reserves to be reduced unilaterally.

Desolation Sound lies within the traditional territory of the Sliammon (Tla'amin) and Klahoose First Nations, who used the area for hunting, gathering and cultural practices for around 10,000 years. From 1875 they were pushed into small reserves, and in 1920 legislation allowed the government to reduce reserve land unilaterally. Their best gathering spots were later leased to oyster farmers, and untreated sewage and fuel leaks from boats have polluted waters where seafood is a primary food source.

The park lies about 32 km north of Powell River and 145 km north of Vancouver, with Lund as the closest community; it is reachable only by boat. Anchorages such as Prideaux Haven and Melanie Cove fill with pleasure craft in summer, when a hundred boats may share one small anchorage. Some inlets, like Theodosia Inlet, show clear-cut logging on shore.

The park's marine waters make up roughly 35 percent of all protected water area in British Columbia. Its forests are mostly second growth after logging, though patches of original old growth remain, with trees often covered in lichen and moss.