Greater Chennai Metropolitan Area, or simply the Chennai Metropolitan Area (CMA), is fourth-most populous metropolitan area in India and the 35th most populous in the world. The CMA consists of the core city of Chennai, which is coterminous with the Chennai district, and its suburbs in Kanchipuram, Chengalpattu, Thiruvallur and Ranipet districts. The Chennai Metropolitan Development Authority (CMDA) is the nodal agency that handles town planning and development within the metro area. In 1974, an area encompassing 1,189 km2 (459 sq mi) around the city was designated as the metropolitan area which was subsequently expanded to 5,904 km2 (2,280 sq mi) in 2022.

Chennai, formerly known as Madras, is the capital city of Tamil Nadu, the southernmost state of India. It is the state's primate city and is located on the Coromandel Coast of the Bay of Bengal. According to the 2011 Indian census, Chennai is the sixth-most populous city in India and forms the fourth-most populous urban agglomeration. Incorporated in 1688, the Greater Chennai Corporation is the oldest municipal corporation of India and the second oldest in the world after London.