Westmeath Provincial Park, Provincial park in Renfrew County, Canada.

Westmeath Provincial Park is a non-operating provincial park on Bellows Bay of the Ottawa River in Renfrew County, Ontario. It protects a sandspit, sand dunes and wetlands on the river's south shore near the town of Westmeath, with a long sandy beach. The dunes are considered the best remaining example along the Ottawa River.

The dunes and sandspit formed from sand laid down by the Ottawa River near the end of the last ice age, when the Great Lakes drained east through the Ottawa Valley. Near Pembroke the river entered the Champlain Sea and built a delta of sand and clay, so the dunes partly trace an ancient ocean shoreline. The park opened in 1991 after the Federation of Ontario Naturalists pushed for a nature reserve; it received Natural Environment classification, and 47% is managed as Nature Reserve.

The park houses 300 plant species and serves as a nature study area for ecological research on wetland plant communities and wildlife populations.

The park has no facilities, no parking lot and no marked trails; access is from the water or by unmarked routes. Overnight camping is not permitted. Spring floods shape the shoreline, and fragile dune plants are easily damaged by foot traffic and all-terrain vehicles.

Before the park opened in 1991, the Federation of Ontario Naturalists pushed for a "Nature Reserve" designation with maximum protection and minimal human use. The Ministry of Natural Resources instead gave it a "Natural Environment" classification, which allowed hunting, swimming and a proposed parking lot; under the management plan, 47% of the park is designated as Nature Reserve.