Mar Sebastian Valloppilly, born on 4th August, 1911, at Kodakkachira in the diocese of Palai had his secular studies at S.B. College, Changanassery and St. Xavier's College Palayamkottah and Ecclesiastical studies at Papal Seminary, Kandy. He was ordained priest on 24th August 1945 and nominated Apostolic Administrator of Tellicherry on 31st December 1953. He took charge of the diocese on 19th March 1954. He was elected the first bishop of Tellicherry on 16th October 1955 and consecrated on 8th January 1956 at St. Peter's Basilica, Rome by His Eminence Eugene Cardinal Tissarant. The diocese enjoyed his fruitful leadership for 33 years.

           He sent his resignation letter to the Holy See on 4th August 1986 when he completed his 75 years of age, and his resignation was accepted on 18th February 1989 when Mar George Valiamattam was appointed his successor.

           He was well known for his Gandhian way of life and commitment to temperance movement. Many secular awards were presented to him in recognition of his valuable services to the community in particular and society at large. His autobiography, 'Daivam Nammodukoode' (God Is With Us) portraits the true picture of Malabar migration of the middle of the 20th century. After his retirement he lived in the Archbishop's house giving inspiration and consolation to thousands of his spiritual children. On 4th April 2006 he departed for his eternal reward.