The Dutch have warmly embraced the prince's new bride
The 34-year-old heir to the Dutch throne exchanged vows with Maxima Zorreguieta, 30, in a civil ceremony at Amsterdam's former stock exchange.
Absent from the celebrations was Maxima's father, Jorge Zorreguieta, who was a minister in Argentina's brutal military dictatorship of Jorge Videla.
The bride wore an ivory-coloured silk gown made by Valentino couture with a five-metre lace train, carrying a bouquet of white roses.
Willem-Alexander wore his dark blue Navy uniform.
Princess warned
The civil ceremony was carried out by the Mayor of Amsterdam, Job Cohen.
He warned the new princess of the Netherlands that she would be "living in a glass house" and said the couple would have to find a balance between private and public life.
After the couple had exchanged vows, Queen Beatrix signed the wedding act as Maxima's witness.
The bride's eyes welled with tears as the ceremony ended.
Among the guests were the UK's Prince of Wales, UN Secretary General Kofi Annan and former South African President Nelson Mandela.
Also there were the kings of Sweden, Norway and Belgium and the queen of Denmark, along with Japan's Crown Prince Naruhito and Jordan's Queen Noor, the widow of King Hussein.
Gilded carriage
The streets outside were a mass of orange as about 80,000 spectators waited in the winter sunshine for a glimpse of the couple.
After the formal ceremonies, they rode through Amsterdam in a gilded carriage, escorted by more than 200 police and royal grenadiers on foot and on horseback.
As the couple emerged on to a balcony of the Royal Palace, many in the crowd waved small plastic flags saying "kiss".
They did, and the crowd cheered.
"This makes the royal family more alive," said Jaap de Bruijn, 35, as he waited for a glimpse of the couple.
"Beatrix is a bit distant. But now the monarchy has become more of the people."
A huge security operation had been put in place to safeguard the route of the procession.
Police erected 11 kilometres (7 miles) of fences and barricades and emergency laws gave police extra powers to search buildings.
The Dutch have warmly embraced Maxima, an investment banker, since the royal engagement was announced last March.
Adoring crowds turned out when the couple embarked on a whistle-stop tour of the country.
Loyal to father
Buenos Aires-born Maxima met Willem-Alexander at a party in Spain.
The romance caused uproar when the political past of Maxima's father was revealed, but she distanced herself from the junta while staying loyal to her father.
Before the engagement was announced, the Dutch Government asked Mr Zorreguieta to agree not to attend the wedding.
It is not the first time a Dutch royal wedding has caused controversy.
Riots accompanied the 1966 marriage of Queen Beatrix and the German-born Prince Claus, who had served in the Hitler Youth before World War II.