The CSI was inaugurated on 27 September 1947 at St. George's Cathedral Chennai, only a month after India achieved its independence from the United Kingdom. It was formed from the union of the South India United Church (itself a union of churches from the Congregational, Presbyterian and Reformed traditions) and the southern provinces of the Anglican Church of India, Pakistan, Burma and Ceylon and the Methodist Church of South India. In the 1990s, a small number of Baptist and Pentecostal churches also joined the union.
When C.S.I. was inaugurated there were fourteen dioceses. Today the church has twenty-two dioceses and more than 2 million members. There are eight dioceses in Tamil Nadu, six in Andhra Pradesh, four in Kerala, three in Karnataka, and one in Sri Lanka.
The logo of the CSI is a cross superimposed on a stylized lotus and surrounded by the motto and the name of the church. The symbols of the lotus and the Christian cross used in the logo possess a rich cultural heritage in India and is used to symbolize the call and mission of the CSI.