The French former-teacher looked stunning in a white and black suit.
The look exemplified the chic style that Brigitte is well-known for.
Brigitte’s white tuxedo jacket featured black lapels and buttons.
She added black skinny trousers to the look, as well as black stilettos.
The French First Lady clutched a black bag with a bejewelled clasps.
Sparkling jewellery could be seen on her fingers as he played with the buttons on her jacket.
NATO Secretary General Jens Stoltenberg, his wife Ingrid, and Angela Merkel were there, among others.
The NATO leaders and their wives and partners were allreaded to a dinner at The Parc du Cinquantenaire, in Jubelpark Park in Brussels.
Brigitte Macron wore a white skirt suit earlier in the day.
The ageless First Lady of France showed off her tanned legs in the outfit.
She was attending a concert at the Queen Elisabeth Music Chapel in Waterloo.
Melania Trump wore a blue dress to join Brigitte and all the other NATO spouses at the musical event.
The US First Lady opted for a navy blue Calvin Klein calf-length dress with white and green detail on the lapel and white Louboutin heels with their trademark red soles.
The meeting has seen leaders from all the countries in the North Atlantic Treaty Organization (NATO) come together.
At the event Donald Trump has urged the members to commit more to military spending.
The US President has tweeted: “What good is NATO if Germany is paying Russia billions of dollars for gas and energy?
“Why are there only 5 out of 29 countries that have met their commitment?
“The U.S. is paying for Europe’s protection, then loses billions on Trade. Must pay 2 per cent of GDP IMMEDIATELY, not by 2025.”