The San Isidro festivities are the most important of the year in the city. They are held in honor of the patron saint of Alcobendas, San Isidro. They last approximately 5 to 7 days (depending on the edition), with the main days being May 14 and 15. During the festivities, a multitude of events and celebrations are organized, creating a packed program for all audiences. To ensure safe festivities, there is a Self-Protection Plan, video surveillance zones, police reinforcements, and a civil protection field hospital. In addition, a free bus service is offered during the San Isidro festivities.
Regarding the patron saint, it is worth mentioning that the centenary of the canonization of San Isidro took place in 2022, specifically on March 12.