Egidio Vagnozzi was born in Rome to Francesco and Pasqua (née Jachetti) Vagnozzi, and studied at the Minor Seminary, Pontifical Roman Seminary, and Pontifical Lateran University (from where he obtained doctorates in philosophy, theology, and canon law). Ordained a priest by Cardinal Rafael Merry del Val on 22 December 1928, Vagnozzi, at age 22, required a dispensation to be ordained, not having yet reached the canonical age. He then finished his studies in 1930.^{[citation needed]}

In 1930, he also became a staff member of the Secretariat of State in the Roman Curia, and was raised to the rank of Privy Chamberlain of His Holiness on 1 May 1932. Before becoming counselor of the Portuguese nunciature in 1942, he was a staff member of the apostolic delegation to the United States in 1932. Vagnozzi was counselor of the French nunciature from 1945 to 1947, and became a Domestic Prelate of His Holiness on 23 December 1945. He was an official of the delegation for the establishment of diplomatic relations with India for a year until becoming chargé d'affaires of the Holy See's mission to the Indian government in New Delhi from June to August 1948.^{[citation needed]}

On 9 March 1949, Vagnozzi was appointed Nuncio to the Philippines and Titular Archbishop of Myra. He received his episcopal consecration on the following 22 May from Cardinal Adeodato Giovanni Piazza, OCD, with Archbishops Francesco Borgongini Duca and Roberto Ronca serving as co-consecrators. On 9 April 1951 – following the establishment of diplomatic relations between the Holy See and the Philippines government, he was appointed the first Apostolic Nuncio to the Philippines.^[1] Vagnozzi was named Apostolic Delegate to the United States on 16 December 1958.^[2] He attended the Second Vatican Council from 1962 to 1965.^{[citation needed]}

Pope Paul VI created him cardinal deacon of S. Giuseppe in via Trionfale in the consistory of 26 June 1967, and President of the Prefecture for the Economic Affairs of the Holy See on 13 January 1968. After ten years' as a cardinal deacon, Vagnozzi exercised his right to become a cardinal priest, and his deaconry was elevated pro hac vice on 5 March 1973. He was one of the cardinal electors who participated in the conclaves of August and October 1978, which selected Popes John Paul I and John Paul II respectively. He was also Chamberlain of the College of Cardinals from 30 June 1979 until his death.

Vagnozzi died in Rome, at age 74. After a funeral Mass presided by John Paul II in the Lateran Basilica, he was buried in the Campo Verano. His remains were later transferred to his cardinalitial church in March 1983.

As the Vatican in modern times came under the criticism of the liberal press for reactionary policies, so was Vagnozzi accused in a 1967 press article for using his influence at the Vatican so as to permit only conservative US priests to become bishops: "His influence is thought to be heavily responsible for the conservative cast of those bishops appointed (in the United States) in recent years".^[3]

Vagnozzi opposed the Marian apparition of Our Lady Mediatrix of All Graces, rejecting its Marian visionary Teresita Castillo, along with six Filipino local bishops who declared it "Non-Supernatural" in 1956. On 11 December 2015, the Vatican confirmed "the definitive nature of the 11 April 1951 decree by which the phenomena of Lipa were declared to lack supernatural origin."^[4]

• Catholic-Hierarchy ^{[self-published]}
• Cardinals of the Holy Roman Church
• Letter of Pope John-Paul II to Cardinal Vagnozzi on the 5Oth anniversary of his priestly ordination
• 1966 interview with Vagnozzi on liturgical reforms Archived 3 March 2012 at the Wayback Machine