Church of South India, Christian denomination formed in 1947 by merger of part of the Anglican Church of India, Burma (Myanmar), and Ceylon (Sri Lanka); the South India province of Methodism; and the South India United Church, itself a 1908 merger of Presbyterian, Dutch Reformed, and Congregationalist groups. Other, smaller groups joined later. In the early 21st century, membership was about 3.8 million with approximately 14,000 congregations and 21 dioceses. The church has congregations in North America as well.
The Church of South India was the first union since the Reformation between episcopal and non-episcopal churches, which aroused passionate and continuing controversy. Conversations with Baptists aimed at extending the union lapsed, but agreement was reached with Lutherans on doctrinal points, though not on all questions of organization. The church is in full communion with the non-episcopal bodies from which in part it sprang but not with all Anglicans.
The union was based on the acceptance of the Holy Scriptures as the supreme authority in faith and life, of the Nicene Creed as the authorized summary of the faith, of the sacraments of baptism and Holy Communion, and of the historic episcopate as the basis for church government. Provision was made for a 30-year period of growing together, in the course of which it was hoped that the union would become complete. On the day of the merger, nine new bishops, drawn from all the traditions, were consecrated to serve with the five Anglican bishops already in office.
No attempt was made to impose uniformity at once on all the local churches, which were to continue to use their accustomed liturgical forms until genuinely Indian forms of worship could be worked out. The church later issued orders for Holy Communion, baptism, and other services. These were not mandatory, but use of them expanded steadily.