Mario Giardini (4 December 1877 – 30 August 1947) was an Italian prelate of the Catholic Church who served in the diplomatic service of the Holy See from 1918 to 1933.
[citation needed] He was a member of the Barnabites and early in his career worked as a parish priest and master of novices for his order.
[1] On 21 November 1921, Pope Pius XI named him titular archbishop of Edessa and Apostolic Delegate to Japan.
[citation needed] He called a provincial synod to address the question of Catholic participation in Shinto ceremonies and the first Japanese bishop, Januarius Kyunosuke Hayasaka, was appointed in 1926.
[3] Negotiations toward the establishment of diplomatic relations made progress but were blocked by Buddhist opposition in parliament.