Silvio Angelo Pio Oddi (14 November 1910 in Morfasso, near Piacenza, Italy – 29 June 2001 in Cortemaggiore) was a diplomat in the service of the Holy See and a cardinal.
After the required theological studies, which he began in his home diocese of Piacenza, Silvio Oddi was ordained a priest on 21 May 1933 in Rome. After three further years of study at the Pontifical Ecclesiastical Academy in Rome, he entered the diplomatic service of the Holy See in 1936 and was assigned to the Apostolic Delegation to Iran until 1939. From that year until 1945 he held a similar post in Syria and Lebanon, then in Egypt (1945-1948), and France (1948-1951). He became head of the Apostolic Nunciature to Yugoslavia in 1951. On 30 July 1953, Pope Pius XII named him Titular Bishop of Mesembria and Apostolic Legate for Jerusalem, Palestine, Transjordan and Cyprus. On 27 September of the same year, he received episcopal ordination from Angelo Giuseppe Roncalli, the future Pope John XXIII. He became Internuncio to Egypt in 1957, Nuncio to Belgium and Internuncio to Luxembourg in 1962.
As a bishop, he took part in the Second Vatican Council (1962-1965), at the conclusion of which Pope Paul VI created him a cardinal on 28 April 1969, assigning to him the titular church of Sant'Agata de' Goti and naming him Papal Legate for the Patriarchal Basilica of Saint Francis in Assisi, as well as giving him responsibility for the shrine of Loreto. He became Prefect of the Congregation for the Clergy on 28 September 1979, a post he held until retirement in 1986. In 1989 he attended, as Papal Legate, the funeral of Japanese Emperor Hirohito.
He died on 29 June 2001, and was buried in the parish church of Morfasso.