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.

Poonamallee is a town and suburb of Chennai, India under the Chennai Metropolitan Area. It was historically called Pushpagirimangalam, later renamed in Tamil as Poovirundhavalli, and now colloquially called as Poondhamalli. It is the headquarters of the Poonamallee taluk of the Tiruvallur district in the Indian state of Tamil Nadu. The nearest Railway station is at Avadi. It acts as the gateway to the city from its western side. It is a town with rich cultural heritage and also a fast-growing areas in the city. As of 2011, the town had a population of 57,224. There are plans to merge the areas under Poonamallee Municipality with Avadi Municipal Corporation.