Palacio de Pedro I, Medieval palace in Cuéllar, Spain.

Palacio de Pedro I is a 13th-century Romanesque building on Calle del Colegio, between the Plaza Mayor and the Mercado del Pan. A 1662 description records two towers flanking a small walled enclosure; one tower has since disappeared. The surviving structure is considered by some historians the best-preserved civil Romanesque palace in Spain.

The first record of the complex dates from 1348, when Don Juan Manuel donated it to Elvira Blázquez, wife of Pedro González Dávila, head of the Velázquez de Cuéllar lineage. In April 1354 Peter I of Castile married Juana de Castro in the church of San Martín and held the wedding banquet in this building. The king abandoned her the next day, yet she kept the title of queen for life.

The building is known as Pedro I because the king held his wedding banquet here in April 1354, after marrying Juana de Castro in the church of San Martín; she kept the title of queen for life. The Velázquez family called it Casa de la Torre from the 17th century.

The palace now operates as a Business Incubator housing spaces for young entrepreneurs and hosts cultural activities throughout the year. Visitors should check beforehand whether visits are possible during current events or exhibitions.

In the early 20th century, the palace was transformed into a chicory factory before the City Council acquired and restored it in 1998. This industrial period shows how the building served practical purposes through different eras.