The Chennai Mofussil Bus Terminus or CMBT (Tamil: சென்னை புறநகர் பேருந்து நிலையம்) is a modern bus terminus located in Chennai, India, providing outstation transportation services. Spread over an area of 37 acres (150,000 m²) in Koyambedu, it is the largest bus terminus in Asia and is accredited with the ISO 9001:2000 quality certification for its quality management and excellence. It is located on the 100 feet (30 m) inner-ring road (Jawaharlal Nehru Road) in Koyambedu between SAF Games Village and the Koyambedu Vegetable Market. Chennai Metro Rail is planning for its coach depot behind CMBT.

The CMBT foundation stone was laid by the then Chief Minister M.Karunanidhi on 6 June, 1999. The CMBT was planned and built by the Chennai Metropolitan Development Authority at a cost of  1,030 million and inaugurated on 18 November 2002 by the then Chief Minister of Tamil Nadu J.Jayalalitha.

The terminus has 6 platforms in 3 bus fingers with 180 bus bays. It also has an idle parking area for 60 buses and can station 270 buses at any given time. Being the most important entry-exit point of the city, the terminus has a capacity to handle over 2,000 buses and 200,000 passengers a day. The terminus currently handles more than 500 buses at a time, and 3,000 buses and 250,000 passengers a day. The 36.5-acre (148,000 m²) bus terminus has an 17,840 sq ft (1,657 m²) waiting facility for passengers, a 25,000 sq ft (2,300 m²) parking space for auto rickshaws, cabs and private cars, and 16,000 sq ft (1,500 m²) parking space for two-wheelers. The amenities provided in the terminus include 3 hotels and 3 smaller eateries inside the terminus, 3 locker rooms, 10 travel agency offices, shops, supermarkets, ATMs, dorm rooms (A/C and non-A/C) for rent, toilets, round-the-clock security, pure drinking water free of cost facilitated by a reverse-osmosis treatment plant, a 24-hour pharmacy, and first-aid facilities and medical assistance. Wheel chairs are provided for the physically disabled.