The Full Form of CMDA is Chennai Metropolitan Development Authority.

The Chennai Metropolitan Development Authority (CMDA), formerly known as the Madras Metropolitan Development Authority (MMDA), is the nodal planning agency of Chennai in the Indian state of Tamil Nadu. The CMDA administers the Chennai Metropolitan Region, spread over an area of 1,189 km² (459 sq mi) and covers the districts of Chennai, Thiruvallur and Kancheepuram. It was set up for the purposes of planning, co-ordination, supervising, promoting and securing the planned development of the Chennai Metropolitan Area. It coordinates the development activities of the municipal corporations, municipalities and other local authorities.