Đồng Tháp is a province in the Mekong Delta, Việt Nam. It has a 50 kilometer border with Prey Veng province (Cambodia) in the North, Tây Ninh province in the Northeast, Hồ Chí Minh city in the east (separated by the Soài Rạp river), South China Sea, Vĩnh Long province in the South, An Giang province in the West, and Cần Thơ city in the Southwest.
The Mekong Delta (Vietnamese: Đồng bằng Sông Cửu Long, lit. 'Nine Dragon River Delta' or simply Đồng Bằng Sông Mê Kông, 'Mekong River Delta'), also known as the South-western Region (Vietnamese: Tây Nam Bộ) or the Western Region (Vietnamese: Miền Tây), is the region in southwestern Vietnam where the Mekong River approaches and empties into the sea through a network of distributaries. The Mekong delta region encompasses a large portion of south-western Vietnam, of an area of over 40,500 km (15,600 sq mi). The size of the area covered by water depends on the season. Its wet coastal geography makes it an important source of agriculture and aquaculture for the country.
The delta has been occupied as early as the 4th century BC. As a product of Khmer, Vietnamese, Chinese, and French settlement in the region, the delta and its waterways have numerous names, including the Khmer term Bassac to refer to the lower basin and the largest river branch flowing through it. After the 1954 Geneva Conference, Vietnam was split into two with South Vietnam inheriting the southern half of Vietnam becoming the State of Vietnam and eventually the Republic of Vietnam, also known as South Vietnam, with their own administrative states (see Category:Provinces of South Vietnam). After 1975, the Mekong Delta ceased being a part of the Republic of Vietnam, succeeded by the current Vietnamese nation. The region comprises 4 provinces: Đồng Tháp, An Giang, Vĩnh Long, and Cà Mau, along with the province-level municipality of Cần Thơ.