The Duke of Beja is a noble title in Portugal, historically associated with the region of Beja in the Alentejo. The title was created in the 15th century and has been held by various members of the Portuguese royal family. It signifies a rank of nobility and is part of the broader system of titles in the country. The title is often linked to the House of Aviz, a significant royal house in Portugal. The most notable holder of the title was Prince Henry the Navigator, who played a crucial role in the early days of the Portuguese Empire and exploration during the Age of Discovery.