All Saints' Day, celebrated on November 1st, is a solemn Catholic holy day dedicated to honoring all the saints of the Church, both known and unknown, who have reached heaven. Instituted in the early centuries of Christianity, it was officially established by Pope Gregory III in the 8th century, designating this day to honor all saints and bless the relics housed in the chapel of St. Peter’s Basilica.

In the Catholic faith, All Saints' Day is a Holy Day of Obligation, meaning Catholics are encouraged to attend Mass to celebrate the lives of the saints and to seek their intercession. This day serves as a reminder of the call to holiness for all believers, inspired by the examples of those who led lives of faith, virtue, and charity. All Saints' Day is part of the triduum of Hallowtide, which includes All Souls' Day on November 2, dedicated to praying for the souls in purgatory. Together, these days form a period of reflection, prayer, and communion with the faithful, living and deceased.