Oreste Marengo (29 August 1906 - 30 July 1998) was an Italian Roman Catholic prelate and professed member from the Salesians of Don Bosco. He served as the Bishop of Diburugarh from 1951 until his transferral in 1964 to Tezpur where he served until 1969. From that point until 1979 he served as the apostolic administrator for the new Tura see. He was dedicated since his childhood to joining the missions and in his late adolescence was permitted to go to the missions in India. Marengo often trekked on foot to remote villages where he evangelized to the people and provided for their educational needs as best he could. He was reluctant to accept his episcopal nomination but did not cease his catechizing and evangelizing in his dioceses. His time spent in India saw him learn prior to his ordina