But he is predisposed to praise the bridal gown because his company owns fashion house Givenchy, which made the dress for Meghan, Duchess of Sussex, who married Prince Harry on Saturday. It was designed by the label's artistic director, Clare Waight Keller.
"I think the dress is marvelous and I think also it fits perfectly what the new princess represents: modernity, diversity and a sense of understated elegance and the result was absolutely marvelous," he told CNBC's Karen Tso at the Viva Tech conference in Paris on Thursday.
More than 29 million Americans watched the royal wedding at Windsor Castle in England last Saturday, according to Nielsen data, with 15 channels airing the ceremony. The measure is the number of people who tuned in when it started at midday local time (7 a.m. EST) and finished at 1:15 p.m.
The fashion house was founded by Hubert de Givenchy in 1952 and its designs have been worn by famous names including Grace Kelly and former First Lady Jackie Kennedy.
Asked whether Givenchy saw a "Gucci effect," or a big moment on social media, Arnault said: "I think Givenchy is a symbol of elegance since Hubert de Givenchy. You know, Hubert was friends with Audrey Hepburn so it's understated elegance and it's an elegance which is timeless.
"So it lasts for a long time… We try to stay for the long run."
Arnault clashed with rival Francois-Henri Pinault, who runs French luxury group Kering, at the turn of the millennium. Both were bidding for ownership of Gucci, with Pinault winning the battle, but it is the LVMH-owned Louis Vuitton label that is the world's largest luxury brand by revenues.
Luxury groups, like many companies, want to make sure they are using cutting-edge technology to reach shoppers. LVMH is running an innovation award program at Viva Tech, with the winner given the chance to meet with personnel at the luxury group. It also led the latest funding round for fashion search engine and data company Lyst, it was announced Thursday, according to an emailed statement.
- CNBC's Sarah Berger contributed to this article.