The Vatican has announced the theme chosen by Pope Leo XIV for World Missions Day 2026: “One in Christ, united in mission.” The worldwide celebration in 2026 will mark the 100th anniversary of the Day’s establishment by Pope Pius XI at the suggestion of the Pontifical Society for the Propagation of the Faith.
Vatican News
“One in Christ, united in mission” is the theme of World Mission Sunday, which next year will commemorate the 100th anniversary of its establishment by Pius XI at the suggestion of the Pontifical Society for the Propagation of the Faith.
On final day of the month traditionally dedicated to missions, the theme chosen by the Pope Leo XIV for the next World Missions Day has been made public. The annual celebration is fixed on the penultimate Sunday of October, which in 2026 falls on 18 October.
Appeal of Pope Leo XIV
In his appeal this year in support of World Mission Sunday, Pope Leo emphasized that it is a privileged occasion for the entire Church to join in prayer for missionaries and for the fruitfulness of their apostolic work. The Pope, recalling his personal experience as a priest and later as a missionary bishop in Peru, stated: “I saw first-hand how the faith, the prayer, and the generosity shown on World Mission Sunday can transform entire communities.”
A guiding thread for all initiatives
The theme of World Mission Sunday 2026, whose first part recalls the motto chosen by the Pope for his pontificate — “In Illo uno unum” (In the one Christ we are one) — highlights the unity of believers in faith, founded on the unity of Christ with the Father, and the consequent common mission of evangelization.
The next step in preparing for World Mission Sunday 2026 will be the release, in the early months of 2026, of the Holy Father’s message, which will serve as the guiding thread for the many initiatives aimed at fostering missionary spirit and responsibility among all the faithful throughout this important year.
During 2026, the Church will also celebrate the 110th anniversary of the foundation of the Pontifical Missionary Union, defined by Saint Paul VI as “the soul of the other Pontifical Missionary Works” — the Society for the Propagation of the Faith, Society of the Holy Childhood and Society of Saint Peter the Apostle. Together, these four societies, each with its own particular mission, work to promote missionary responsibility among the baptized and to support new local Churches.
