This article addresses the Saint Thomas Christian Churches and denominations that form the Nasrani people or Saint Thomas Christians.

The Saint Thomas Christians are an ancient body of Christians from Kerala, India, who trace their origins to the evangelistic activity of Thomas the Apostle in the 1st century. They are also known as "Nasranis" because they are followers of "Jesus of Nazareth". The term "Nasrani" is still used by St. Thomas Christians in Kerala.