Mar Thoma I, also known as Valiya Mar Thoma and Arkkadiyakkon Thoma in Malayalam and Thomas de Campo in Portuguese was the first native-born, popularly-selected Metropolitan bishop of the 17th-century Malankara Church. He was the last Archdeacon of the undivided St. Thomas Christians of Malankara (Maliyankara).

The Malankara Metropolitan or the Metropolitan of Malabar is an ecclesiastical title given to the head of the Malankara Syrian Church. It evolved from the title of the sixteenth century East Syriac metropolitans of India who were also styled the Metropolitan of Malabar. Since the division among the Saint Thomas Christians following the Synod of Diamper, the title has been mostly employed in association with the West Syriac branch of the community, usually known as the Malankara Church, among whom the office of the Malankara Metropolitan became the continuation of the local dynastic Archdeaconate.