Grass Hills National Park, National park in Western Ghats, India

Grass Hills National Park is a national park in the Western Ghats of southern India, also recognized as part of a UNESCO World Heritage Site. It sits at high elevation and consists of open montane grasslands surrounded by dense forest.

The area was designated as a national park to protect the rare montane grasslands and forests of southern India, which faced growing pressure from human activity. Its later inclusion in the UNESCO World Heritage Site gave the protection an international dimension.

The park is part of the Anamalai Tiger Reserve and forms the boundary with Eravikulam National Park in Kerala. Despite its name, it is not an official national park. Its shola-grassland ecosystem, found only in the higher ranges of the Western Ghats, is what visitors come to see.

A permit is required to access the trekking routes inside the park, so it is worth arranging this in advance. A guided tour is recommended because the trails are remote and the terrain can be demanding.

The park is not an official national park at all: it is a protected area of about 65,000 hectares that forms part of the Anamalai Tiger Reserve and borders Eravikulam National Park in Kerala. Its Tamil name, Pul Malai, simply means "grass hills".