Sinharaja Forest Reserve is a forest reserve and a biodiversity hotspot in Sri Lanka. It is of international significance and has been designated a Biosphere Reserve and World Heritage Site by UNESCO.

According to International Union for Conservation of Nature (IUCN), Sinharaja is the country's last viable area of primary tropical rain forest. More than 60% of the trees are endemic and many of them are considered rare. 50% of Sri Lankan's endemics species of animals (especially butterfly, amphibians, birds, snakes and fish species). It is home to 95% endemic birds.