World Day of Peace

The Catholic Church, sometimes referred to as the Roman Catholic Church, is the largest Christian church, with approximately 1.3 billion baptised Catholics worldwide as of 2018. As the world's oldest and largest continuously functioning international institution, it has played a prominent role in the history and development of Western civilization. The church is headed by the Bishop of Rome, known as the pope. Its central administration is the Holy See.

The Christian beliefs of Catholicism are found in the Nicene Creed. The Catholic Church teaches that it is the One, Holy, Catholic and Apostolic church founded by Jesus Christ in his Great Commission, that its bishops are the successors of Christ's apostles, and that the pope is the successor to Saint Peter upon whom primacy was conferred by Jesus Christ. It maintains that it practises the original Christian faith, reserving infallibility, passed down by sacred tradition. The Latin Church, the twenty-three Eastern Catholic Churches, and institutes such as mendicant orders, enclosed monastic orders and third orders reflect a variety of theological and spiritual emphases in the church.

The World Day of Peace is a feast day of the Roman Catholic Church dedicated to universal peace, held on 1 January, the Solemnity of Mary, Mother of God. Pope Paul VI established it in 1967, being inspired by the encyclical Pacem in Terris of Pope John XXIII and with reference to his own encyclical Populorum Progressio. The day was first observed on 1 January 1968.

World Day of Peace often has been an occasion on which the Popes made magisterial declarations of social doctrine. Pope Paul VI and Pope John Paul II made important declarations on the Day in each year of their pontificates regarding the United Nations, human rights, women's rights, labor unions, economic development, the right to life, international diplomacy, peace in the Holy Land (Israel), globalization, and terrorism.

In different years were the following messages World Day of Peace:

- Peace as a journey of hope: dialogue, reconciliation and ecological conversion;
- Good politics is at the service of peace;
- Migrants and refugees: men and women in search of peace;
- Nonviolence: a Style of Politics for Peace;
- Overcome Indifference and Win Peace;
- No longer slaves, but brothers and sisters;
- Fraternity, the Foundation and Pathway to Peace.

In England and Wales, "Peace Sunday" is traditionally observed on the Second Sunday of Ordinary Time, which is the Sunday occurring between 14 and 20 January, inclusive. The British branch of the Pax Christi movement prepares suggested material for it annually.