Brahmo Samaj (brä´mō səmäj´) [Hindi,=society of God], Indian religious movement, founded in Kolkata (Calcutta) in 1828 by Rammohun Roy. It promoted a monotheistic, reformed Hinduism with strong Islamic and Christian overtones, support for the rights of women, and opposition to such aspects of Hinduism as idolatry and animal sacrifice. Under Roy the organization attained considerable importance in E India until his death in 1833. After a decade of decline, it was revived by Debendranath Tagore in 1843. A schism divided the organization in 1865, when Keshub Chunder Sen split with Tagore and formed the Adi Brahmo Samaj, and in 1878 Sen's group itself divided. Sen's followers formed a new church, the Nava-Vidhana, while the dissidents founded the Sadharan Brahmo Samaj, which became dominant. The Brahmo Samaj movement had great influence in the 19th cent., but although it still exists, it has had little impact on 20th-century Hinduism.
See P. K. Sen, Biography of a New Faith (2 vol., 1950–54); K. C. Sen, The Voice of Keshub (1963); P. V. Kanal, An Introduction to Dev-Samaj (1965).