An immense majority (98 percent) of the people of Bangladesh is Bengalis and they speak the Bengali language. Minorities include Biharis numbering 250,000 and other tribes numbering about a million, with the Chakma being most frequent in number. About 83 percent of Bangladeshis are professing Islam as their religion. The next foremost religion is Hinduism (16 precent). Other major religions consist of Buddhism and Christianity.

 A portion of the Indo-European family of languages, Bangla (sometimes called Bengali) is the official language of Bangladesh. Bangladeshis closely categorize themselves with their national language. Bangla has a rich cultural inheritance in literature, music, and poetry, and at least two Bengali poets are well known in the West: Rabindranath Tagore, a Hindu and a Nobel laureate; and Kazi Nazrul Islam, a Muslim known as the “voice of Bengali patriotism and independence.” Bangla has been enriched by several regional dialects. The dialects of Sylhet, Chittagong, and Noakhali have been strongly noticeable by Arab-Persian influences. English, whose cultural influence seemed to have crested by the late 1980s, remained nevertheless an important language in Bangladesh.

Biharis, a group that integrated Urdu-speaking non-Bengali Muslim refugees from Bihar and other parts of northern India, numbered about 1 million in 1971 but had decreased to around 600,000 by the late 1980s. They once subjugated the upper levels of Bengali society. Many also held jobs on the railroads and in heavy industry. As such they stood to lose from Bangladesh independence and sided with Pakistan during the 1971 war. Hundreds of thousands of Biharis were repatriated to Pakistan after the war.

Bangladesh’s tribal population consists of about 1 million people, just fewer than 1 percent of the total population. They live primarily in the Chittagong Hills and in the regions of Mymensingh, Sylhet, and Rajshahi. The majority of the tribal population (778,425) lives in rural settings, where many practice shifting farming. Most tribal people are of SinoTibetan tumble and have idiosyncratic Mongoloid facial appearance. They differ in their social organization, marriage customs, birth and death rites, food, and other social customs from the people of the rest of the country. They speak Tibeto-Burman languages. In the mid-1980s, the percentage allocation of tribal population by religion was Hindu 24, Buddhist 44, Christian 13, and others 19.

The four largest tribes are the Chakmas, Marmas (or Maghs), Tipperas (or Tipras), and Mros (or Moorangs). The tribes lean to intermingle and could be eminent from one another more by differences in their dialect, dress, and customs than by tribal consistency. Only the Chakmas and Marmas display formal tribal organization, although all groups contain different clans. By far the largest tribe, the Chakmas are of mixed origin but reflect more Bengali influence than any other tribe. Unlike the other tribes, the Chakmas and Marmas generally live in the highland valleys. Most Chakmas are Buddhists, but some adept Hinduism or animism. Bangladesh is one of the largest Muslim countries in the world. Most Bangladeshi Muslims are Sunnis, but there is a small Shia population. Among religious festivals of Muslims Eidul Fitr, Eidul Azha, Eiday Miladunnabi, Muharram etc. are high-flying. The controversy that Bengali Muslims are all descended from lower-caste Hindus who were converted to Islam is incorrect; a substantial proportion are descendants of the Muslims who reached the subcontinent from elsewhere.