Ralegan Siddhi is a village in Parner taluka of Ahmednagar District, Maharashtra state in western India. It is located at a distance of 87 km from Pune. The village has an area of 982.31 ha (1991). It is considered a model of environmental conservation. The village has carried out programs like tree planting, terracing to reduce soil erosion and digging canals to retain rainwater. For energy, the village uses solar power, biogas (some generated from the community toilet) and a windmill.
The project is heralded as a sustainable model of a village republic.