The Malankara Orthodox Syrian Church (MOSC) also known as the Indian Orthodox Church (IOC) or simply as the Malankara Church, is an autocephalous Oriental Orthodox church headquartered in Devalokam, near Kottayam, India. It serves India's Saint Thomas Christian population. According to tradition, these communities originated in the missions of Thomas the Apostle in the 1st century. It employs the Malankara Rite, an Indian form of the West Syriac liturgical rite.

Catholicos of the East and Malankara Metropolitan are the titles used by the Malankara Orthodox Syrian Church, which is also called the Indian Orthodox Church, for the same bishop holding two offices of Catholicos of the East and Malankara Metropolitan. The term "Catholicos" is derived from the Greek word Katholikos (Καθολικός), meaning "Universal Bishop". His Holiness Baselius Marthoma Mathews III is the present Catholicos of the East and Malankara Metropolitan.