The Baptist Missionary Society was founded in 1792 by William Carey (1761-1834). As a youth, Carey had developed an interest in missionary work in the South Seas through reading the accounts of Captain Cook's 1769-1770 voyages to that region. This interest was accentuated when Carey read Jonathan Edwards' book Life of Brainerd. In 1792, Carey himself authored a paper, "An Inquiry into the Obligations of Christians to use Means for the Conversion of the Heathen." His two sermons in that year, one before the Baptist Association at Nottingham and the other before the Baptist Association at Kettering, were impassioned pleas for missions, and these are generally credited with spurring the interest in others which resulted in the founding of the Baptist Missionary Society on October 2, 1792.

The original intent of the Society was to foster mission work in the South Seas, but this was given up when a definite burden was felt for the heathen of India. In March 1793 William Carey sailed with John Thomas (1757-1792) and they landed in Calcutta in November of that year. Work was concentrated in the areas of Bible translation, preaching, teaching, and the founding of schools. It was not until 1800, however, that Carey baptized the first Hindu convert. In 1810 the India work was organized into five missions, and by 1813 the Society could report sixty-three workers, native and European, involved in twenty mission stations. Two other men heavily involved in organizing the India work were Joshua Marshman (1768-1837) and William Ward (1769-1823).

A mission begun in Sierra Leone in 1795 proved to be abortive. Work was not resumed in West Africa until 1842, when stations were founded both on the Spanish island of Fernando Po, and in Cameroon. Spanish authorities halted the Fernando Po mission in 1858. The Cameroon work continued until 1887, when German colonization there paved the way for the Basle Missionary Society to take over that mission. In 1878, the Baptist Missionary Society entered the Congo and Angola. Missionaries were forced to withdraw from both areas in 1961.

A mission was begun on Ceylon in 1812. In 1813 the West Indies work was begun in Jamaica, followed by mission stations in British Honduras (1822), the Bahamas (1833), Trinidad and the Dominican Republic (both 1843), and Haiti (1845). A mission was founded in France in 1834; other European stations later included Norway and Italy. Attempts to place missionaries in China were not successful at first, but work was established there by 1877. The Society extended itself into Japan in 1879 and into Palestine in 1880. With the Communist takeover in China in 1949, the Society withdrew from there and sought to continue its mission to the Chinese people via Hong Kong. In 1853, work was begun in Brazil. The Society also participated with other mission boards in Nepal and Sierra Leone missions.

Bible translation and publishing were important functions of the Society. By William Carey's death in 1834, it had already translated the entire Bible into forty languages and dialects. Joshua Marshman translated the Bible into Chinese and prepared a Chinese grammar and dictionary. In addition, many sacred texts of the Chinese and Hindus were translated into English. The Society's publishing arm, the Carey Press, was in 1847 amalgamated with the Kingsgate Press of the Baptist Union of Great Britain and Ireland to form the Carey Kingsgate Press Limited.