The Alcázar de Luis de Chaves el Viejo, also called Fortified House of the Chaves or simply Alcázar de los Chaves, is a defensive building located in the town of Trujillo belonging to the province of Cáceres in the Autonomous Community of Extremadura.

The Alcázar or "casa fuerte" is attached to the walls of the town of Trujillo, next to the door of Santiago. After the initial construction in the 14th century, during the reign of King Alfonso XI, it was rebuilt in the following century by Luis de Chaves and its current appearance almost coincides with that which resulted from the reconstruction.

The Catholic Kings were lodged in this fortress when they visited Trujillo in the years 1477 and 1479. It has a large Homage Tower that defended the "Puerta de Santiago". In later centuries it was inhabited by the "Brothers of the Sacred Heart of Jesus" and, later, asylum in the elderly.