Arnault was born in Roubaix, France, on March 5, 1949.
Arnault graduated from the École Polytechnique in Palaiseau, with a M.Sc, degree in 1971.
After graduation in 1971, Arnault joined his father's company (Ferret-Savinel).
Arnault married Anne Dewavrin in 1973.
Using the name Férinel, the new company developed a specialty in holiday accommodation.
Arnault Named the Director of Company Development in 1974.
In 1976, Arnault convinced his father to liquidate the construction division of the company for 40 million French francs and to change the focus of the company to real estate.
Arnault became the CEO of Férinel in 1977.
In 1979, Arnault succeeded his father as president of the company.
In 1984, with the help of Antoine Bernheim, a senior partner of Lazard Frères, Arnault acquired the Financière Agache, a luxury goods company.
Arnault became the CEO of Financière Agache and subsequently took control of Boussac Saint-Frères, a textile company in turmoil.
Boussac owned Christian Dior, the department store Le Bon Marché, the retail shop Conforama, and the diapers manufacturer Peaudouce.
Arnault sold nearly all the company's assets, keeping only the prestigious Christian Dior brand and Le Bon Marché department store.
In 1987, shortly after the creation of LVMH, the brand new luxury group resulting from the merger between two companies, Arnault mediated a conflict between Alain Chevalier, Moët Hennessy's CEO, and Henri Racamier, president of Louis Vuitton.
In July 1988, Arnault provided $1.5 billion to form a holding company with Guinness that held 24% of LVMH's shares.
In July 1988, Arnault acquired Céline.
On 13 January 1989, he was unanimously elected chairman of the executive management board of LVMH.
Arnault divorced Anne Dewavrin in 1990.
In September 23, 1991, Arnault married Hélène Mercier.
In 1993, Arnault bought out the French economic newspaper La Tribune.
In 1996, Arnault bought out Loewe.
From 1998 to 2001, Arnault invested in a variety of web companies such as Boo.com, Libertysurf, and Zebank through his holding Europatweb.
Groupe Arnault invested in Netflix in 1999.
Arnault decided to develop a centre in New York to manage LVMH's presence in the United States.
The result was the LVMH Tower that opened in December 1999.
Arnault's collection includes work by Picasso, Yves Klein, Henry Moore, and Andy Warhol. He was also instrumental in establishing LVMH as a major patron of art in France.
In 2006, Arnault started the building project of the Louis Vuitton Foundation. Dedicated to creation and contemporary art, the building was designed by the architect Frank Gehry.
In 2007, Blue Capital announced that Arnault owns jointly with the California property firm Colony Capital acquired 10.69% of France's largest supermarket retailer and the world's second-largest food distributor Carrefour.
Arnault sold La Tribune in November 2007 in order to buy a different French economic newspaper, Les Échos, for 240 million euros.
In 2008, Arnault entered the yacht business and bought Princess Yachts for 253 million euros.
In 2008, Arnault took control of Royal van Lent for approximately 253 million euros.
From 2010 until 2013, Arnault was a member of the Board of Advisors of the Malaysian 1MDB fund.
In 2013, it was disclosed that Arnault planned to apply for Belgian citizenship and was considering moving to Belgium.
In April 2013, Arnault said that he had been misquoted and that he never intended to leave France.
On 10 April, 2013, Arnault announced that he had decided to abandon his application for Belgian citizenship, saying he did not want the move to be misinterpreted as a measure of tax evasion at a time when France faced economic and social challenges.
Arnault's family pledged €200 million to help repair the Notre-Dame cathedral after a fire, said a statement issued on behalf of Arnault.
In November 2019, Arnault planned to acquire Tiffany & Co. for approximately US $16.2 billion. The deal was expected to close by June 2020.
LVMH then issued a statement in September 2020 indicating that the takeover would not proceed and that the deal was "invalid" because of Tiffany's handling of the business during the COVID-19 pandemic.
In mid-September 2020, a reliable source told Forbes (magazine) that the reason for Arnault's decision to cancel the Tiffany purchase was purely financial: Tiffany was paying millions in dividends to shareholders despite a financial loss of US$32 million during the pandemic. Upon examination of financial records, Arnault discovered that some US$70 million had already been paid out by Tiffany, with an additional US$70 million scheduled to be paid in November 2020.
In late October 2020, Tiffany and LVMH agreed to the original takeover plan, though at a slightly reduced price of nearly $16 billion, a minor reduction of 2.6% from the aforementioned deal. The new deal reduced the amount paid per share by LVMH from the original price of $135 to $131.50.
LVMH completed the purchase of Tiffany in January 2021.
Under Arnault's leadership, LVMH has grown to become the largest company by market capitalization in the Eurozone, with a record of 313 billion euros ($382 billion) as of May 2021.
Arnault has promoted decisions towards decentralizing the group's brands as a business strategy. As a result of these measures, brands under the LVMH umbrella such as Tiffany are still viewed as independent firms with their own history. For a very brief period on May 24, 2021, Arnault temporarily became the richest man in the world, surpassing Jeff Bezos with a net worth of 187.3 billion dollars. A few hours later, however, Amazon stock ticked up and Jeff Bezos retook the spot and reclaimed it.