St. Stephen's Day is a public holiday in San Marino that is celebrated every year on the 26th of December. This holiday comes a day after Christmas and is a day dedicated to St. Stephen, who is recognized as a saint in Christianity. St. Stephen is known to be one of the first Deacons of the Christian Church and he is revered as the first martyr of Christianity.

San Marino being one of the oldest republics and deeply rooted in Christian traditions, marks St. Stephen's Day with great significance. Churches around the country host special services for holidaygoers to gather and remember the life and contributions of Saint Stephen. As it falls during the festive season, people also enjoy the holiday relaxing, visiting family, and sharing meals together. Even though it's a Christian holiday, the cultural context extends the celebration to everyone in the country.

The events for St. Stephen's Day vary. Many citizens attend the special services that include readings and teachings about St. Stephen. Additionally, homes and streets are often spotted with leftover decorations from Christmas, adding to the festive atmosphere. Notably, as the day after Christmas, the holiday also provides an extra day for people to unwind and relax from the Christmas celebration. As this holiday is largely a quiet, family-oriented day, it adds a peaceful note to the end of the festive season in San Marino.