Thoma I was a 17th-century Eastern Orthodox priest who served as the first native-born Metropolitan bishop of the Malankara Church. Born into the Parampil family of Kuravilangad, he succeeded his uncle as archdeacon during a period of significant ecclesiastical tension. He is best known for leading the Coonan Cross Oath, a pivotal movement that asserted the independence of the Saint Thomas Christians from Jesuit and Portuguese colonial administration. He eventually sought and received formal consecration through the Syriac Orthodox Church of Antioch.