St. Stephen's Day is a national holiday in Andorra, celebrated every year on the 26th of December. This holiday is dedicated to the memory of Saint Stephen, the first Christian martyr. Andorran tradition holds that Stephen was a deacon in the early Christian church who was stoned to death for his religious beliefs, hence achieving sainthood. This holiday signifies the end of a long Christmas Day celebration, and it is commonly known amongst locals as 'Boxing Day'.

The Andorran celebration of St. Stephen's Day is characterized by religious activities, including attending mass. Many people devote the day to spending time with family and friends which often includes sharing meals and exchanging gifts. Some also take advantage of the holiday to go outside and enjoy the snow, skiing being a popular pastime in the region. St. Stephen's Day is essentially a day of relaxation and enjoyment.

Many businesses close in observance of St. Stephen's Day in Andorra, as it's a public holiday, allowing residents time to engage in the aforementioned traditions and activities. For those visiting Andorra during this time, they can have a unique insight into the country’s cultural heritage, religious devotion, and familial values. St Stephen's Day is indeed an essential part of Andorran living, a day that showcases the nation's rich traditions and strong Christian faith.