An heir apparent is one who cannot be prevented from inheriting by the birth of any other person. Contrast with heir presumptive.
According to the order of succession of many monarchies, the heir apparent is a descendant of a monarch who is the heir to their throne, whose status as heir cannot be defeated by the birth of someone else who would then become the heir. An heir apparent differs from an heir presumptive in that, although an heir presumptive inherits the throne upon the death of the monarch, the right of the heir presumptive could be defeated by the birth of another person who would then be the heir apparent. For example, in Britain, if the monarch has a daughter and no sons, the daughter is the heiress presumptive, who becomes Queen if the monarch dies. But if the monarch later has a son, the son is then the heir apparent. In most monarchies, the monarch's oldest son, even if not the oldest child, becomes heir apparent. A growing number of monarchies, however, now allow the monarch's oldest child, irrespective of sex, to become heir apparent. Where that heir has died leaving children, their oldest child (or oldest son) becomes heir apparent.
It is an error to call the heir apparent simply the "heir." The heir is the person who currently owns the estate, having inherited it— in this case, the currently reigning monarch.
Heir apparent is a technical term that is not used as an actual title. The most common title used for heirs apparent in kingdoms is Crown Prince. In the case of full cognatic primogeniture, such as in Sweden, Norway and Belgium, a woman can be heir apparent, and thus Crown Princess.
In monarchies that are not kingdoms, other titles like Hereditary Grand Duke or Hereditary Prince are used in stead.
However, many countries have specially designed titles for the heir apparent. Such titles may be automatically assigned, like Prince of Orange in the Netherlands, or traditionally granted by the monarch, like Prince of Wales in the United Kingdom. A more extensive list of these titles is available in the Crown Prince article.
- HRH The Prince Charles, Prince of Wales is the heir-apparent to the Thrones of the United Kingdom and of fifteen other Commonwealth Realms.
- HRH Prince Philippe, Duke of Brabant is the heir-apparent to the Throne of Belgium.
- HRH The Infante Felipe, Prince of the Asturias is the heir-apparent to the Throne of Spain.
- HRH Haakon Magnus, Crown Prince of Norway is the heir-apparent to the Throne of Norway
- HRH Crown Princess Victoria, Duchess of Westrogothia is the heiress-apparent to the Throne of Sweden
- HRH Prince Willem-Alexander is the heir-apparent to the Throne of the Netherlands.
- HRH Crown Prince Naruhito is the heir-apparent to the Chrysanthemum Throne (the Throne of Japan).