Kolli Hills or Kolli Malai (Tamil: கொல்லி மலை) is a small mountain range located in central Tamil Nadu in Namakkal district of India. The mountains rise to 1300m in height and cover an area of approximately 280 km². They are part of the Eastern Ghats, which is a mountain range that runs mostly parallel to the east coast of South India.
The mountain is a site of pilgrimage, because of the Arapaleeswarar temple, but the area is also popular with hikers.
It is an area of outstanding natural beauty and Annas Fund are working with local workers to provide education and also education on nutirition for the poorest people that exist on subsistence farming. Small project help them by paying them.