Net worth: $41 billionForbes billionaires rank: 4

Nationality: French

Background: Arnault, the chairman of luxury conglomerate LVMH, whose stable of brands includes fashion powerhouse Louis Vuitton. He also owns stakes in Bulgari, Hermes, and Carrefour.

In addition to being the fourth richest man in the world, he’s also the richest man in Europe.

Net worth: $31 billion
Forbes billionaires rank: 7

Nationality: Spain

Background: Ortega is the former chairman of Indetix, the firm that owns fashion retailers including Zara, Massimo Dutti and Stradivarius, and has 5,000 stores in 77 countries.

Net worth: $26.5 billion

Forbes billionaires rank: 10

Nationality: U.S.

Background: Walton is the heir to the Wal-Mart empire, and while the discount big box retailer is not exclusively in the fashion business, it makes a big enough chunk of change selling apparel that we included her in this list.

Apparel made up around 10% of Wal-Mart’s overall sales in 2010, or about $25.8 billion.

Net worth:$24.5Forbes billionaires rank: 13

Nationality: Swedish

Background: Persson is the chairman of cheap-chic retailer Hennes & Mauritz (H&M), which has 2,200 stores worldwide and is known for collaborating with A-list designers from Karl Lagerfeld to Jimmy Choo.

Net worth:$23.5 billionForbes billionaires rank: 15

Nationality: French

Background: Fashion and beauty are inextricably intertwined, and L’Oreal heir Liliane Bettencourt owes her largess to the global cosmetics company founded by her father.

Net worth: $12.7 billion
Forbes billionaires rank: 60

Nationality: U.S.

Background: Knight, the co-founder of Nike, started by selling running sneakers out of his car and eventually expanded into a footwear and athletic wear empire that did $19 billion in sales last year.

Net worth:$11.5 billion

Forbes billionaires list: 67

Nationality: French

Background: Pinault, a high school dropout, is the majority shareholder of luxury goods conglomerate PPR. Holdings include Gucci, Yves Saint Laurent and Puma.

He’s also the owner of auction house Christie’s, and husband of actress Salma Hayek.

Net worth: $11 billion
Forbes billionaires rank: 71

Nationality: Italian

Background: Del Vecchio is the founder of Luxottica, the world’s largest manufacturer of sunglasses and prescription eyeglasses, as well as the world’s biggest eyewear retailer.

His company owns over 6,000 retail stores, including Sunglass Hut and LensCrafters.

Net worth: $7.6 billion
Forbes billionaires rank: 122

Nationality: Japanese

Background: Yanai is the founder and president of Fast Retailing, which counts the hugely popular apparel retailer Uniqlo among its subsidiaries.

Net worth: $7.2 billion
Forbes billionaires rank: 132

Nationality: U.K.

Background: The Greens own Topshop, the popular British retail chain that made a huge splash when it landed in New York in 2009.

Phil’s not only interested in apparel–he’s currently in the process of launching a reality show with Simon Cowell.

Net worth: $7.1 billion
Forbes billionaires rank: 133

Nationality: Canadian

Background: Weston’s retail empire isn’t strictly apparel, but it includes department store powerhouses such as Holt Renfrew in Canada, Brown Thomas in Ireland and Selfridges in the U.K.

He’s also reportedly interested in buying Barneys New York.

Net worth: $7 billion
Forbes billionaires rank: 136

Nationality: Italian

Background: The designer is also a shrewd businessman. He unveiled a megastore on Manhattan’s Fifth Avenue in 2009 and lent his aesthetic (and name) to a chain of hotels, including one that recently opened in Dubai.