Rudolf, Crown Prince of Austria, heir apparent to the throne of Austria-Hungary (born 1858)

Rudolf, Crown Prince of Austria was the only son and third child of Emperor Franz Joseph I and Empress Elisabeth of Austria. He was heir apparent to the imperial throne of the Austro-Hungarian Empire from birth. In 1889, he died in a suicide pact with his mistress Baroness Mary Vetsera at the Mayerling hunting lodge. The ensuing scandal made international headlines.

An heir apparent is a person who is first in the order of succession and cannot be displaced from inheriting by the birth of another person. A person who is first in the current order of succession but could be displaced by the birth of a more eligible heir is known as an heir presumptive.