Tiny Marsh Provincial Wildlife Area, Protected wetland habitat in Ontario, Canada.

Tiny Marsh Provincial Wildlife Area covers 8.5 square kilometres of marsh, open water, bog and upland forest about three kilometres inland from Nottawasaga Bay near Elmvale. Its 25 kilometres of trails lead over dikes to two observation towers, a marsh viewing mound and a boardwalk, and a nature centre displays the marsh's flora and fauna.

The site became Ontario's first provincially owned and managed wetland, setting a turning point for conservation efforts in the region. This status established a model that influenced how other wetlands in the province would be protected.

Around 250 bird species have been recorded at Tiny Marsh, among them the pied-billed grebe, trumpeter swan, sandhill crane, and the provincially threatened least bittern and black tern. Ospreys nest here alongside 11 species of ducks, and visitors also watch for milksnake, northern watersnake and red-bellied snake. The nature centre displays the marsh and its flora and fauna.

The site is accessible from multiple parking areas with trails of varying difficulty levels throughout the property. Wear appropriate footwear since terrain can be muddy and slippery, especially during wetter seasons.

Tiny Marsh is one of roughly 1,200 Important Bird Areas recognised in Canada, and ospreys nest here alongside 11 duck species. Visitors have also recorded milksnake, northern watersnake and red-bellied snake. The provincially threatened least bittern and black tern are among the birds seen at the marsh.