Bangladesh, officially the People's Republic of Bangladesh, is a country in South Asia. It is surrounded by India on all sides except for a small border with Myanmar to the far southeast and the Bay of Bengal to the south. Together with the Indian state of West Bengal, it makes up the ethno-linguistic region of Bengal. The name Bangladesh means "Country of Bengal"

The borders of Bangladesh were set by the Partition of India in 1947, when it became the eastern wing of Pakistan (East Pakistan), separated from the western wing by 1,600 km (1,000 miles). Despite their common religion of Islam, the ethnic and linguistic gulf between the two wings, compounded by an apathetic government based in West Pakistan, resulted in the independence of Bangladesh under the leadership of Sheikh Mujibur Rahman in 1971 after the bloody Bangladesh Liberation War, in which it was supported by India. The years following independence have been marked by political turmoil, with thirteen different heads of government, and at least four military coups.

The population of Bangladesh ranks eighth in the world, but its area of approximately 144,000 km² is ranked ninety-fourth, making it one of the most densely populated countries in the world. It is the third largest Muslim-majority nation, but has a slightly smaller Muslim population than the Muslim minority in India. Geographically dominated by the fertile Ganges-Brahmaputra Delta, the country has annual monsoon floods, and cyclones are frequent. Bangladesh is one of the founding members of South Asian Association for Regional Cooperation (SAARC), BIMSTEC, and a member of the OIC and the D-8.

Bangladesh is located in the low-lying Ganges-Brahmaputra River Delta or Ganges Delta. This delta is formed by the confluence of the Ganges (local name Padma or Pôdda), Brahmaputra (Jamuna or Jomuna), and Meghna rivers and their respective tributaries. The alluvial soil deposited by these rivers has created some of the most highly fertile plains of the world.

Most parts of Bangladesh are within 10 metres above the sea level, and it is believed that about 10% of the land would be flooded if the sea level were to rise by 1 metre. [20] The highest point in Bangladesh is in Mowdok range at 1,052 m (3,451 ft) in the Chittagong Hill Tracts to the southeast of the country.[21] A major part of the coastline comprises a marshy jungle, the Sundarbans, one of the largest mangrove forests in the world and home to diverse flora and fauna, including the Royal Bengal Tiger. In 1997, this region was declared endangered. [22]

Straddling the Tropic of Cancer, Bangladeshi climate is tropical with a mild winter from October to March, a hot, humid summer from March to June. A warm and humid monsoon season lasts from June to October and supplies most of the country's rainfall. Natural calamities, such as floods, tropical cyclones, tornadoes, and tidal bores occur almost every year, combined with the effects of deforestation, soil degradation and erosion. Cox's Bazar, south of the city of Chittagong, has a beach that stretches uninterrupted over 120 kilometres (75 mi); it is one of the longest unbroken natural sea beaches of the world.