Fernando Cento was born in Pollenza, Italy. His parents were Evaristo Cento and his second wife, Ermelinda Andreani. He had a half-sister, Rosa, and a brother, Vincenzo.
He was educated at the Seminary of Macerata from 1893 to 1905, where he was taught philosophy and theology, and later at the Pontifical Gregorian University, where he studied canon law. He continued his studies at La Sapienza University, Rome where he obtained a doctorate in letters. He received the diaconate on 17 December 1905 in the basilica of the Madonna della Misericordia.
Priest
He was ordained on 23 December 1905 in Macerata; he had to obtain a dispensation for being not yet 23. He served as professor of literature at the Seminary of Macerata and of philosophy at the State Institute of Macerata from 1906 to 1916. He demonstrated excellent qualities as a preacher in several Italian dioceses. He was called to military service when Italy entered the First World War in 1915 and was attached to the military hospital of Ancona from 1915 to 1917. He was created Privy chamberlain of His Holiness on 15 November 1917.
He was promoted to Titular Archbishop of Seleucia Pieria on 24 June 1926 and was appointed Apostolic Nuncio to Venezuela four days later. He was next named Apostolic Nuncio to Peru on 26 July 1936. In addition, he was responsible for the affairs of the church in Ecuador, which did not have diplomatic relations with the Holy See for nearly forty years. He was named nuncio to Ecuador on 25 July 1937 once the Ecuadorian government and the Holy See established diplomatic relations.