Mitlenatch Island Nature Provincial Park, Provincial nature park on an island in Strait of Georgia, Canada.

Mitlenatch Island Nature Provincial Park is a protected natural area on an island in the Strait of Georgia off the coast of British Columbia. The terrain includes upland ridges, rocky shores, and sheltered coves that support diverse habitats for seabirds and marine wildlife.

In 1959 the province of British Columbia bought Mitlenatch Island from a local family, and in 1961 it was designated a Provincial Nature Park. The island lies in the northern Strait of Georgia, about 30 km northeast of Courtenay, within the Strathcona Regional District. The protected area covers 155 hectares, of which 36 hectares are upland and 119 hectares are foreshore.

The name Mitlenatch comes from the Coast Salish First Nations language, referring to the sheltered waters surrounding the island. Visitors can sense this cultural connection when exploring the coastal landscape that indigenous communities have valued for generations.

Access to the park is only by boat, and visitors should prepare for unpredictable weather and rough water conditions. A single marked trail connects two bays and is the only publicly accessible area, as the rest of the park is reserved for protected nesting sites.

Mitlenatch holds the largest seabird colony in the Strait of Georgia, where glaucous-winged gulls, pelagic cormorants, pigeon guillemots, rhinoceros auklets and black oystercatchers return each spring to breed. Some of British Columbia's largest garter snakes live here and are often seen along trails and in tide pools, feeding on sculpins and blennies.