The Mekong Delta ("đồng bằng sông Cửu Long" in Vietnamese-Nine Dragon river delta)is the region in Southeast Vietnam where the Mekong River approaches and empties into the sea through a network of tributaries. The Mekong delta region encompasses a large portion of southeastern Vietnam of 39,000 km². The area covered by water depends on the season.

During the Vietnam War, the Delta region saw fighting between NLF guerrillas and units of the United States Navy operating in small river boats.