The Buckingham Canal is a salt water navigation canal, running parallel to the Coromandel Coast of South India for 420 km, from Krishna District in Andhra Pradesh to South Arcot district in Tamil Nadu. The canal connects most of the natural backwaters along the coast to the port of Chennai (Madras). It was constructed by the British, and was an important waterway during the British Raj.

The first segment of the canal was constructed in 1806, from Chennai north to Ennore . Subsequently, it was extended north to Pulicat Lake, 40 km north of Chennai. The canal was taken over by the government of Madras Presidency in 1837 and further extended, ultimately reaching 315 km north of Chennai to Peddaganjam on the Krishna River in Krishna District of Andhra Pradesh, and 103 km south of Chennai to Marakkanam in Tamil Nadu. The canal runs approximately 1 km back from the coastline. The Cooum river connects the canal to the Bay of Bengal in the center of Chennai. The portion north of the Cooum is known as the North Buckingham Canal, and the portion south of the Cooum as the South Buckingham Canal. 257 km of the canal are in Andhra Pradesh, and 163 km are in Tamil Nadu. Approximately 31 km are within the city limits of Chennai.

The canal was formerly used to convey goods up and down the coast to Chennai. The cyclones of 1965/1966 and 1976 damaged the canal, and it is presently little used and no longer maintained. Within the city of Chennai the canal is badly polluted from sewage and industrial effluent, and the silting up of the canal has left the water stagnant, creating an attractive habitat for malaria-bearing mosquitos. The North Chennai Thermal Power Station (NCTP) discharges hot water and fly ash into the canal as well. On January 1 2001 the Government of India launched a project to prevent sewage outfalls into the canal and Chennai's other waterways, and to dredge the canal to remove accumulated sediment and improve water flow.