Willem-Alexander was born in Utrecht during the reign of his maternal grandmother, Queen Juliana, as the eldest child of Princess Beatrix and Prince Claus.

He is the first man to hold this position since the death of his great-great-grandfather William III in 1890, as the intervening three monarchs—his great-grandmother Wilhelmina, his grandmother Juliana and his mother Beatrix—had all been women.

He lived with his family at the castle Drakensteyn in the hamlet Lage Vuursche near Baarn from his birth until 1981, when they moved to the larger palace Huis ten Bosch in The Hague.

[5][9] After his military service from 1985 to 1987, Willem-Alexander studied history at Leiden University from 1987 onwards and received his Master of Arts degree (doctorandus) in 1993.

[10][11] His final thesis was on the Dutch response to France's decision under President Charles de Gaulle to leave NATO's integrated command structure.

[12] Between secondary school and his university education, Willem-Alexander performed military service in the Royal Netherlands Navy from August 1985 until January 1987.

[16] On 10 October 2010, Willem-Alexander and Máxima went to the Netherlands Antilles' capital, Willemstad, to attend and represent his mother, the Queen, at the Antillean Dissolution ceremony.

On the morning of 30 April 2013 (Koninginnedag), Beatrix signed the instrument of abdication at the Moseszaal (Moses Hall) at the Royal Palace of Amsterdam.

Later that afternoon, Willem-Alexander was inaugurated as king before a joint session of the States General in a ceremony held at the Nieuwe Kerk.

Willem-Alexander was one of four new sovereign monarchs in 2013 along with Pope Francis, Emir Tamim bin Hamad Al Thani of Qatar, and King Philippe of Belgium.

[21][23] Using the name "W. A. van Buren", one of the least-known titles of the House of Orange-Nassau, he participated in the 1986 Frisian Elfstedentocht, a 200-kilometre-long (120 mi) distance ice skating tour.

The marriage triggered significant controversy due to the role the bride's father, Jorge Zorreguieta, had in the Argentinian military dictatorship.

In an attempt to strike a balance between privacy for the royal family and availability to the press, the Netherlands Government Information Service (RVD) instituted a media code on 21 June 2005 which essentially states that:[29] During a ski vacation in Argentina, several photographs were taken of the prince and his family during the private part of their holiday, including one by Associated Press staff photographer Natacha Pisarenko, in spite of the media code, and after a photo opportunity had been provided earlier.

On 28 August 2009, the district court ruled in favour of the prince and RVD, citing that the couple has a right to privacy, that the pictures in question add nothing to any public debate, and that they are not of any particular value to society since they are not photographs of his family "at work".

[31] In October 2020, Willem-Alexander apologised for a family holiday trip to Greece which had taken place while his country was under partial lockdown during the COVID-19 pandemic.

[32] Earlier in August, he and his wife were photographed with a restaurant owner during another trip to Greece, which was a violation of social distancing rules at the time.

[36] The development project was aimed at building an ecologically responsible vacation resort, including a hotel and several luxury holiday homes for investors.

Through his mother, Willem-Alexander also descends from Paul I of Russia and thus from German princess Catherine the Great and Swedish King Gustav I.

[71][72] Willem-Alexander is a descendant of King George II and, more relevant for his succession rights, of his granddaughter Princess Augusta of Great Britain.

Under the British Act of Settlement, King Willem-Alexander temporarily forfeited his (distant) succession rights to the throne of the United Kingdom by marrying a Roman Catholic.