The Immaculate Conception is a public holiday in Spain and is observed on the 8th of December each year. It is a Catholic religious holiday which celebrates the belief that the Virgin Mary was conceived without any sin. The holiday is known in Spanish as 'La Inmaculada Concepción' and is deeply rooted within Spanish culture and religion, as Catholicism is one of the country’s major religions.

The celebration of the Immaculate Conception in Spain is filled with various traditional rituals and customs. It is common for Spanish families to go to church on this day, with services often filled to capacity. Many towns and cities across the country hold processions and other public events. Additionally, some areas even have special regional traditions. For example, in Seville, they have the traditional 'Dance of the Seises', a historic and ritual dance performed by boys in 16th-century attire in the Cathedral of Seville.

The Immaculate Conception actually marks the beginning of the Christmas season in Spain. From this day, it is common to see Spanish homes, streets, and businesses start to get decorated for Christmas. The country goes into festive mode, with lights, wreaths, and Nativity scenes adorning public places. In addition to its religious significance, the holiday provides the Spanish people a respite from work, enabling families to start preparing for the festive season. For Spaniards, it is not just a religious event, but a valued cultural holiday that gives them an opportunity to come together and celebrate their shared heritage.