Kaduthuruthy Marth Mariam Knanaya Major Archiepiscopal Church, commonly called Kaduthuruthy Valiapally or the Great Church of Kaduthuruthy, is a historic church founded by the Knanaya community in 400 C.E. The Knanaya are the descendants of Syriac Judeo-Christians who migrated from Persian Mesopotamia to Kodungallur, Kerala, during the medieval era.

In 1911 the church was incorporated into Kottayam Knanaya Archeparchy of the Syro Malabar Catholic Church. Due to its historical significance, Kaduthuruthy Valiyapally holds the status of forane, or senior church among Knanaya churches within the Kaduthuruthy region.
In 2020, along with other historic and prominent churches of the Syro Malabar communion, Kaduthuruthy Valiyapally was elevated to major archeparchial status.