Chaldean Syrian Church

The Chaldean Syrian Church of India (Classical Syriac: ܥܕܬܐ ܕܡܕܢܚܐ ܕܐܬܘܖ̈ܝܐ; Malayalam: കൽദായ സുറിയാനി സഭ, romanized: Kaldaya Suriyani Sabha) is an Eastern Christian denomination, based in Thrissur, in India. It is part of the greater Assyrian Church of the East and is organised a singular Metropolitan (Archdiocese) See of India, and represents the part of traditional Christian communities that follow the East Syriac Rite in the Malabar region of India. It is headed by Mar Awgin Kuriakose.

The church uses the East Syriac Rite, and employs the Divine Liturgy of Saints Addai and Mari. Its members constitute a traditional community among Saint Thomas Christians (also known as Nasrani), who trace their origins to the evangelistic activity of Thomas the Apostle in the 1st century. They are based mostly in the state of Kerala, numbering some 15,000 members in the region.

The Chaldean Syrian Church is a modern-day continuation of the historical ecclesiastical province of India, that was active in continuity until the 16th century, as part of the ancient Church of the East. After the long period of internal schisms and struggles, that lasted from the end of the 16th to the beginning of the 20th century, the Church was consolidated during the tenure of Mar Abimalek Timotheus (d. 1945), who is revered as a saint by the Church of the East.