Christian feast days: Pope John XXIII (Roman Catholic Church)

Pope John XXIII was head of the Catholic Church and sovereign of the Vatican City State from 28 October 1958 until his death on 3 June 1963. He is the most recent pope to take the pontifical name "John".

The Catholic Church, also known as the Roman Catholic Church, is the largest Christian church, with 1.27 to 1.41 billion baptized Catholics worldwide as of 2025. It is among the world's oldest and largest international institutions and has played a prominent role in the history and development of Western civilization. The Church consists of 24 sui iuris (autonomous) churches, including the Latin Church and 23 Eastern Catholic Churches, which comprise almost 3,500 dioceses and eparchies around the world, each overseen by one or more bishops. The pope, who is the bishop of Rome, is the chief pastor of the church.