Parque Provincial Pereyra Iraola, Provincial park in Buenos Aires Province, Argentina.

Parque Provincial Pereyra Iraola is a large protected area in the southern part of Buenos Aires Province, spanning across the municipalities of Berazategui, Ensenada, Florencio Varela, and La Plata. The more than ten thousand hectares include wetlands, woodlands, and open grasslands where native plants grow alongside animal species that have become rare in the heavily urbanized region.

The land belonged to the Pereyra Iraola family, who bought the Estancia Las Conchitas from Juana Rita Pinto in 1850 and renamed it San Juan. Leonardo Pereyra began afforesting it in 1860 after studying European parks and gardens. The government of Juan Domingo Perón expropriated 10,138 hectares in January 1949 and inaugurated the Parque de los Derechos de la Ancianidad on 24 February 1950. UNESCO declared the park a Biosphere Reserve in 2008.

The park takes its name from the Pereyra Iraola family, who owned the Estancia San Juan until the 1949 expropriation; a 2012 proposal to rename it after Governor Domingo Mercante was approved by the Buenos Aires Senate. The former Santa Rosa house now serves as the park administration, and 36 buildings from the pre-founding La Plata era survive across the grounds, among them a silo, a nursery, a carpentry shop and a carriage garage.

Visitors should bring sturdy footwear and plenty of drinking water, as the marked paths lead through remote sections. Early morning hours work best for wildlife watching, when birds and other creatures are most active.

The park holds 36 buildings from the era before La Plata was founded, among them the Santa Rosa house that now serves as the park administration, plus an original silo, a nursery, a mechanical workshop, a carpentry shop and a carriage garage. In 2012 the Buenos Aires Senate approved renaming the park after Governor Domingo Mercante, who ordered the expropriation.