Ralegan Siddhi (Marathi: राळेगण सिद्धी) 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.
The village's biggest accomplishment is in its use of non-conventional energy. For example, all the village street lights each have separate solar panels. The village is headed by a Sarpanch who is the chief of the Gram Panchayat (village panchayat).
In 2001, the village had 394 households and a population of 2306 (1265 males and 1041 females).
In 1975 the village was afflicted by drought, poverty prevailed, and trade in illicit liquor was widespread. The village tank could not hold water as the embankment dam wall leaked. Work began with the percolation tank construction. Hazare encouraged the villagers to donate their labour to repair the embankment. Once this was fixed, the seven wells below filled with water in the summer for the first time in memory.