St. Mary's Orthodox Syrian Cathedral (Thumpamon Valiya Pally or തുമ്പമണ് വലിയ പള്ളി) is an ancient church located in Thumpamon near Pandalam, Kerala state of India. It is the headquarters of the Thumpamon Diocese of the Malankara Orthodox Syrian Church. The first church was built in AD 717. The Architectural style of the church is Gothic Revival style.
The first church in Thumpamon was built in AD 717, and the structure of that church was not like present one. The first church was a small prayer hall. As the years passed by, the Nazarene population in Thumpamon increased and in AD 900 the old church building was demolished and a much larger building was constructed in its place. Histories of Thumpamon states that in AD 900 (kollavarsham-350) Thumpamon Pally was built and it was the second structure of the church.