The Spanish royal, who is married to Princess Letizia, has become one of the most popular royals in Europe and is expected to mark his birthday with family and friends.
To honour Felipe's birthday HELLO! Online has compiled a list of ten facts about Spain's future king.
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1. Born in Madrid on 30 January 1968, Felipe was the youngest child of King Juan Carlos and Queen Sofia, who already had daughters Infantas Elena and Cristina.
At the time of his birth, Felipe was not yet heir-apparent as his father had not become king yet.
2. The Prince has explained he has a strong desire to be able to recognise what is important to the people of Spain.
"Some people think I'm too serious, but I believe I've got a sense of humour," he once told HELLO! "I like to think of myself as being no different from anybody else, with my failures, qualities, frustrations, joys, worries, everything... A king should not lose his perception of what it is like to be somebody normal."
3. Like many royals, Prince Felipe has competed in the Olympics. The athletic royal was a member of the Spanish sailing team in 1992 at the Barcelona Games, in the same way his father King Juan Carlos was two decades before.
4. As Spain's future monarch, Felipe currently bears the official titles of Prince of Asturias, Prince of Gerona, Prince of Viana, Duke of Montblanc, Count of Cervera and Lord of Balaguer.
5. In November 2003 it was announced that Felipe was engaged to the then Letizia Ortiz Rocasolano, a well respected and award-winning CNN journalist.
Six months later on 22 May 2004, the couple married in the Cathedral Santa Maria la Real de la Almudena in Madrid.
6. Felipe and Letizia's wedding was watched by 25 million people in Spain alone, and upon marriage Letizia was made a Princess.
7. The prince is godfather to Denmark's Crown Prince Frederik and Crown Princess Mary's third child, Prince Vincent of Denmark and Princess Ingrid Alexandra of Norway, who is the eldest daughter of Crown Prince Haakon of Norway and Crown Princess Mette-Marit.
8. As he turns 46, Felipe will eventually be the oldest king to ascend theSpanish throne. Currently, however, that record belongs to his great-great-great-great-great-great-grandfather Carlos III (1716-1788) who was 43 at the time of his ascension.
9. Felipe, Letizia and their two daughters, Infanta Leonor of Spain, eight, and Infanta Sofía of Spain, six, have been applauded for representing a modern monarchy and the next generation of Spanish royals are popular amongst the people.
10. Prince Felipe also holds a Master's degree in international relations and a Bachelor's degree in Law. Along with Spanish, the prince also speaks fluent French and English.