The Deccan Plateau (Marathi: दख्खन), also known as the Peninsular Plateau, is a large plateau in India, making up the majority of the southern part of the country. It is located between three mountain ranges and extends over eight Indian states. Its uplands make up a triangle nested within the familiar downward-pointing triangle of the Indian sub-continent's coastline. It is technically a vast plateau with a wide range of habitats, encompassing most of central and southern India. It is bounded in the west by the Western Ghats and in the east by the Eastern Ghats which each rise from their respective nearby coastal plains and nearly meet at the southern tip of India. These two formations form the southward-pointing vertex of a triangle which encompasses the plateau with the roughly west-south-west to east-north-east running Satpura Range and Vindhya Range forming the third side of the region. The northern ranges separate the plateau from the heavily populated riverine plains of northern India.

It makes up large areas of the states of Maharashtra and Karnataka and parts of Andhra Pradesh. It has an elevation which ranges from 100 metres in the north to 1000 metres in the south. This region is one of the most geologically stable land masses of the world. The Deccan forms the catchment areas of mighty rivers. The name Deccan is an anglicised form of the Prakrit word , itself derived from the Sanskrit word (Sanskrit: दक्षिण), meaning 'South'.