Princess Leonor is 20! When the Princess of Asturias one day ascends the throne, she will be Spain’s first queen regnant since Queen Isabella II in the 19th century. Back on her 18th birthday, King Felipe and Queen Letizia’s elder daughter swore an oath to the Spanish constitution, declaring that from that day, she owed herself “to all Spaniards, whom I will serve at all times with respect and loyalty.” 

She added, “There is no greater pride. On this important day – which I will always remember with emotion – I ask you to trust me, as I have placed all my trust in our future, in the future of Spain.” 

To celebrate the future Queen turning 20 on October 31, 2025, here are 20 facts about Princess Leonor of Spain.

Princess Leonor of Spain© Getty Images

Leonor turned 20 on October 31, 2025

1.

Leonor holds the title of Princess of Asturias, as well as the titles of Princess of Girona and Princess of Viana and Duchess of Montblanc, Countess of Cervera and Lady of Balaguer.

MADRID, SPAIN - NOVEMBER 07:  In this handout picture from the Casa Real, Prince Felipe of Spain and Princess Letizia hold their newborn daughter Princess Leonor for a photo session November 7, 2005 at the Zarzuela Palace in Madrid, Spain. (Photo by Casa Real via Getty Images)© Getty Images

Leonor is the King and Queen’s first child

2

Leonor was born on October 31, 2005 in Madrid, making King Felipe and Queen Letizia, who married in May 2004, first-time parents. 

“It’s the most beautiful thing that can happen to anyone in life,” Felipe said following the birth of his first child, via UPI. “Seeing your child being born is just amazing. We are radiantly happy.”

Prince Felipe, Letizia and their daughter Leonor in holidays in Lanzarote Island. (Photo by Dusko Despotovic/Corbis via Getty Images)© Corbis via Getty Images

Leonor pictured with her parents in December of 2005

3

According to Royal Central, Felipe explained that they chose the name Leonor because “it has many historical ties” and they “liked it.” In an interview after leaving the hospital, Letizia shared (via Royal Central): “On the list of girl names was Leonor because [Felipe] liked it a lot; it was very exciting for him, and I loved it.”

MADRID, Spain:  Spain's Princess Letizia (L) holds her daughter Leonor as Cardinal Antonio Maria Rouco Varela (R) baptises the child with water from the river Jordan while Spain's Queen Sofia and King Juan Carlos look on at the Zarzuela Palace in Madrid, 14 January 2006.    AFP PHOTO/POOL//Angel Diaz  (Photo credit should read ANGEL DIAZ/AFP via Getty Images)© AFP via Getty Images

Leonor was christened months after her arrival

4

The Princess, whose paternal grandparents, King Juan Carlos I and Queen Sofía of Spain, are her godparents, was christened at the Royal Palace on January 14, 2006.

Princess Leonor and Infanta Sofia© Spanish Royal Household via Gett

Leonor became a big sister in April of 2007

5.

The Princess of Asturias stepped into her new role as big sister in 2007, when Letizia and Felipe welcomed their second child, Infanta Sofia. At the 2025 Princess of Asturias Awards, Leonor remarked that “sister accomplices are our great allies and travel companions.”

MADRID, SPAIN - JUNE 19:  King Felipe VI of Spain (L) attends along side Queen Letizia of Spain, Princess Leonor, Princess of Asturias and Princess Sofia of Spain during his inauguration at the Parliament (Congreso de los Diputados) on June 19, 2014 in Madrid, Spain. The coronation of King Felipe VI is held in Madrid. His father, the former King Juan Carlos of Spain abdicated on June 2nd after a 39 year reign. The new King is joined by his wife Queen Letizia of Spain  (Photo by Juan Naharro Gimenez/Getty Images)© Getty Images

Felipe ascended the throne in 2014

6.

Princess Leonor became first in line to the Spanish throne on June 19, 2014, the day her father Felipe was proclaimed the King of Spain, following his father King Juan Carlos I’s abdication.

TOPSHOT - Spain's King Felipe VI (R) awards Spain's most prestigious awards, the Order of the Golden Fleece (Toison de Oro) which dates from 1430, to his daughter Princess Leonor (L), 12-year-old heir to the throne, during a ceremony at the Royal Palace in Madrid, on January 30, 2018. (Photo by JUAN MEDINA / POOL / AFP) (Photo by JUAN MEDINA/POOL/AFP via Getty Images)© POOL/AFP via Getty Images,JUAN MEDINA/POOL/AFP via Getty Images

The Princess received the Order of the Golden Fleece on her dad’s 50th birthday

7.

When Leonor was 12 years old, her father presented her with the Order of the Golden Fleece. “Today, Leonor, you are taking a very important and symbolic step towards your future role, which began on 19 June 2014, when, by constitutional rights, you were named the Princess of Asturias and given other titles that traditionally belong to the heir to the Spanish throne,” the King told his firstborn. 

He continued: “I know it may seem like you have lots of challenges and responsibilities to face, all important and difficult, but know that you have the support of many people who want the best for Spain, for the Crown and for you. Your family will always be at your side, especially your mother and Sofia, who will be with you, supporting you, as will your grandparents and of course, myself. Know that you have my complete trust and that I feel so immensely proud to have presented this Order of the Golden Fleece to you this morning.”

MADRID, SPAIN - OCTOBER 31:  King Felipe VI of Spain and Princess Leonor of Spain attend the reading of the Spanish Constitution for the 40th anniversary of its approval by the Congress at the Cervantes Institute on October 31, 2018 in Madrid, Spain.  (Photo by Carlos Alvarez/Getty Images)© Getty Images,Carlos Alvarez/Getty Images8.

OVIEDO, SPAIN - OCTOBER 18: Princess Leonor of Spain, King Felipe of Spain, Queen Letizia of Spain and Princess Sofia of Spain attend the Princesa de Asturias Awards 2019 ceremony at the Campoamor Theater  on October 18, 2019 in Oviedo, Spain. (Photo by Carlos Alvarez/Getty Images)© Getty Images

The Princess was 13 when she presided over the Princess of Asturias Awards for the first time

9.

Leonor presided over the Princess of Asturias Awards for the first time in 2019. At the ceremony, Leonor remarked that it was a “very important day” in her life. She said in her speech: “In my house, the words Spain and Asturias are always united with the same force with which history has united them. That’s how I feel it in my heart and that today is a very important day in my life that I have looked forward to.”

MADRID, SPAIN - MARCH 24:  This handout image provided by the Spanish Royal Household shows Princess Leonor, as she deposits the copies of the Constitution and the Quixote in the 'Caja de las Letras' (lit. box of letters) during her visit on occasion of the 30th Cervantes Institute anniversary, her first official act alone as the heiress of the Spanish throne,   on March 24, 2021 in Madrid, Spain.  The Cervantes Institute uses safes in the vault of their headquarters as time capsules to store legacies of personalities of the Hispanic culture. (Photo by Casa de S.M. el Rey Spanish Royal Household via Getty Images)© Getty Images

The royal undertook her first solo engagement in 2021

10.

At 15 years old, the future Queen carried out her first solo engagement on March 24, 2021, visiting the Cervantes Institute as part of its 30th anniversary celebrations. In the Caja de las Letras, Leonor deposited a copy of the Spanish Constitution that she read during her first public speech, as well as a copy of Don Quixote, which she and her sister read during the Covid-19 pandemic. 

LLANTWIT MAJOR, WALES - AUGUST 30: In this handout image provided by the Royal Household, Crown Princess Leonor of Spain starts the school year at UWC Atlantic College on August 30, 2021 in Llantwit Major, Gales, United Kingdom. (Photo by Spanish Royal Household via Getty Images)© Getty Images

The Princess studied in the UK for two years

11.

LLANTWIT MAJOR, WALES - MAY 20: In this handout image provided by the Spanish Royal Household, King Felipe VI of Spain (R), Queen Letizia of Spain (L), Crown Princess Leonor of Spain (2R) and Princess Sofia of Spain (2L) attend the graduation of Princess Leonor of Spain at the UWC Atlantic College  on May 20, 2023 in Llantwit Major, Gales, United Kingdom. The graduation ceremony, known as the "Leavers celebration," marked the end of Princess Leonor's two-year stay in Wales. (Photo by Handout/Spanish Royal Household via Getty Images)© Spanish Royal Household via Gett

The King, Queen and Sofia attended Leonor’s graduation ceremony

12.

The Princess graduated from UWC Atlantic in 2023. Leonor’s proud parents and sister were on hand for her big day. As she made her way to the stage, a teacher said: “Leonor, your love of meaningful conversations knows no bounds. Your unwavering passion for learning, understanding people, and exploring diverse perspectives has truly enriched your UWC experience. We will miss your humor.”

ZARAGOZA, SPAIN - AUGUST 18: In this handout image provided by Spanish Royal Household, Princess Leonor of Spain is seen during her first day in uniform at the General Military Academy on August 18, 2023 in Zaragoza, Spain. (Photo by Casa de S.M. el Rey/Spanish Royal Household via Getty Images)© Spanish Royal Household via Gett

The Princess started her military training in 2023

13.

After obtaining her International Baccalaureate diploma, Leonor began her three-year military training. In a press release, Casa de S.M. el Rey shared that Letizia and Felipe considered Leonor’s training “very convenient and valuable: it reinforces the capacities of service and delivery, and facilitates the representation tasks that she must assume, as Heir to the Crown of Spain, in accordance with the provisions of Title II of the Constitution.”

ZARAGOZA, SPAIN - AUGUST 17:  The Princess of Asturias, Leonor, arrives accompanied by King Felipe VI, Queen Letizia, and her sister Infanta Sofia, at the General Military Academy of Zaragoza on the occasion of her entrance for her military training, on 17 August, 2023 in Zaragoza, Aragon, Spain. The Princess of Asturias begins today her training as a lady cadet at the General Military Academy, joining a new class of cadets, future officers of the Army, the Civil Guard and the Common Corps of the Armed Forces. Leonor will have a special study plan compared to that of the other cadets, since she will take two courses in one year and will have, like her father King Felipe VI, the specialty of infantry. She will join 612 cadets (140 women) in the first promotion, but on October 7, the day of the Oath of Allegiance, she will join the second promotion. In the first weeks of military life, the cadets will acquire basic knowledge of military law and regulations, which they will complement with physical training and military instruction. During the course, Her Royal Highness will stay with the rest of her class in shared quarters with other female students.  (Photo by Toni Galan/Getty Images)© Getty Images

Leonor’s parents and sister dropped her off at the academy

14.

The Princess arrived at the General Military Academy in Zaragoza on August 17, 2023 to begin her first year of military training. 

After her first year, the Princess confessed that she arrived at the General Military Academy “with enthusiasm and a great desire to learn and get to know both my classmates and the other classes with whom I have shared this year.”

“I can tell you that what I have experienced here far exceeds what I thought ten months ago,” she added. “In Zaragoza, in Aragon, I have felt at home, welcomed and accompanied in a land that will always be part of my life. There are only five weeks left until I leave, so I can receive my ensign’s office, and I’m already starting to miss you!”

MADRID, SPAIN - OCTOBER 31: (L-R) The King and Queen of Spain, Felipe VI and Letizia, Princess Leonor, and the Princess of Spain, Felipe VI and Letizia. (Photo By Eduardo Parra/Europa Press via Getty Images)© Europa Press via Getty Images

Leonor pictured on her 18th birthday

15.

The Princess swore an oath to the Spanish constitution in front of the Cortes Generales on her 18th birthday in 2023. “I swear to faithfully carry out my duties, to uphold and ensure that the Constitution and the laws are upheld, to respect the rights of citizens and the Autonomous Communities, as well as loyalty to the King,” she said. 

That day, Leonor was also presented with the Collar de la Real y Distinguida Orden Española de Carlos III (The Royal and Distinguished Spanish Order of Charles III). 

LISBON, PORTUGAL - JULY 12: Portuguese President Marcelo Rebelo de Sousa greets Crown Princess Leonor of Spain in Belem Presidential Palace during the official visit to Portugal by Her Royal Highness the Princess of Asturias on July 12, 2024 in Lisbon, Portugal. This is her first official visit to a foreign country. (Photo by Horacio Villalobos#Corbis/Corbis via Getty Images)© Corbis via Getty Images

The Spanish Princess paid a solo visit to Portugal in 2024

16.

Leonor undertook her first solo official trip abroad to Portugal in July of 2024. In a press release, the Ministry of Foreign Affairs, European Union and Cooperation of Spain noted that “the choice of Portugal as the destination for Her Royal Highness the Princess of Asturias’ first official trip abroad reflects and strengthens the bonds of fraternity and close ties that unite the two countries.”

 Princess Leonor of Spain© 2024 Getty Images

Leonor wrote that she was joining the Naval Military School with great enthusiasm

17.

CADIZ, SPAIN - JANUARY 11: Crown Princess Leonor of Spais says goodbye to her parents on January 11, 2025 in Cadiz, Spain. Princess Leonor will take part in this training cruise as part of her military education, sailing alongside 76 midshipmen and visiting eight countries on a six-month journey covering over 17,000 nautical miles (Photo by Borja B. Hojas/WireImage)© WireImage

Leonor bid farewell to her mom and dad on January 11, 2025 in Cadiz, Spain

18.

Her naval training continued on the Training Ship Juan Sebastián de Elcano in January 2025. Reflecting on her training in July of 2025, Leonor said: “Time has passed very quickly, as the intense months in Marín have been followed by the training cruise on the training ship and the weeks on the frigate. But whether in Marín or at sea, I feel that this year in the Navy has served to strengthen the values of honor, valor, discipline, and loyalty that define our Naval Military Academy.”

MARIN, PONTEVEDRA, GALICIA, SPAIN - JULY 14: The Princess of Asturias Leonor receives the title of "Adoptive Daughter of Marin" granted by the City Council of Marin, at the hands of the Mayoress of Marin, Maria Pilar Ramallo Vazquez, on 14 July, 2025 in Marin, Pontevedra, Galicia, Spain. The title recognizes the historical link between the town and the Royal House, especially because Marin is the seat of the Naval School. This initiative seeks to strengthen the connection between the town and the Crown, and recognizes the importance of Doña Leonor's presence in the town, where she has made several visits. (Photo By Beatriz Ciscar/Europa Press via Getty Images)© Europa Press via Getty Images

Leonor received the title of ‘Adopted Daughter of Marín’

19.

The Princess made history in July 2025 becoming the first “Adopted Daughter of Marín.’ Her father was awarded the title of “Adopted Son of Marín” in 1986 during his training at the Naval Academy.

SAN JAVIER, MURCIA, MURCIA REGIO, SPAIN - SEPTEMBER 01: Princess Leonor enters the General Air Academy, on September 1, 2025, in San Javier, Murcia, Spain. Princess Leonor begins the last course of the three that have consisted of her military training as a future captain general of the Armed Forces when she will accede to the throne. After her passage through the General Academy of the Army in Zaragoza and the Naval Military School of Marin (Pontevedra) last year, which included six months of navigation aboard the training ship 'Juan Sebastian Elcano', the Bourbon ensign enters as a fourth year student to train as a pilot at the General Air Academy of San Javier (Murcia). (Photo By Edu Botella/Europa Press via Getty Images)© Europa Press via Getty Images

The future Queen climbed into the cockpit of a PC-21 Pilatus training aircraft

20.

Leonor began her third and final year of military training at the General Air and Space Academy in San Javier on September 1, 2025. In the Academy’s Book of Honor, the Princess penned: “Today I begin the third stage of my military training at this General Air and Space Academy. I look forward with enthusiasm to this course, during which I will have the opportunity to begin my aeronautical training and, alongside my classmates, learn the practical and theoretical aspects of military aviation.”