It was the first visit by the Catholic King Philippe and his Queen Mathilde to the head of the Church, who has been in office for just under six months.
The royal couple had last received Pope Francis (2013-2025) in their own country.
The Pope's visit in September 2024 caused a diplomatic crisis because Francis harshly condemned the country's liberal abortion laws.
During a visit to the grave of King Baudouin (1930-1993) together with the ruling royal couple, the Pope praised Baudouin's courage in opposing a "murderous" law. He spoke out in favour of the beatification of the Catholic king.
At the same time, Francis called on Belgians to take their cue from Baudouin, even in the current times in which further "criminal laws" have been introduced. The then king had abdicated for 36 hours in 1990 because he refused to sign a law liberalising abortion for reasons of conscience.
On the flight back to Rome, Francis again described abortions as murder and called doctors who perform them "contract killers".
The then Prime Minister then said in the Belgian House of Representatives: "For a foreign head of state to make such a speech in relation to the laws of our country is completely unacceptable."
He continued: "The time when the Church dictated the law is over."
Orban also with Pope Leo
Also on Monday, Leo XIV received Hungarian Prime Minister Viktor Orban for the first time in a private audience.
The head of government then spoke with Cardinal Secretary of State Pietro Parolin and the Vatican's "foreign minister", Archbishop Paul Richard Gallagher.
According to the Vatican, a great deal of space was devoted to European issues.
Particular attention was paid to the conflict in Ukraine and the situation in the Middle East.
The solid bilateral relations and the appreciation of the Catholic Church's commitment to promoting social development and the well-being of Hungarian society were also emphasised.
The focus here was on the role of the family, education and the future of young people.
The importance of protecting the most vulnerable Christian communities was also discussed.
The Hungarian was last received by Pope Francis in an audience at the Vatican in December 2024.
Orban also attended the funeral of the head of the Church on 26 April in St Peter's Square.