At the mere age of 18, eight years after "Keeping up with the Kardashians" debuted on E!, Jenner embarked on her makeup empire, Kylie Cosmetics.
At 21 years old, Jenner's worth hovered around $1 billion, according to Forbes estimates. By comparison, Mark Zuckerberg didn't hit this ten-figure mark until he was 23 years old.
Jenner founded her company in 2015, tapping into her hundreds of millions of social media followers to promote her popular lip liners and liquid lipsticks.
The mogul told Forbes she used $250,000 of her own money that she made from modeling gigs to pay a company to produce the first 15,000 lip kits that she sold online for about $30 a piece.
An internet frenzy erupted seconds after the star launched her products online. The products -- yes, all of them -- sold out in minutes. The heavy demand even crashed the website numerous times.
According to Forbes, after the products sold out, resellers began offering her kits on eBay for upward of $1,000.
"Before I even refreshed the page, everything was sold out," Jenner told the outlet in a 2018 interview.
By the end of 2016, her company, which was less than a year old, was selling roughly 50 products and raking in a revenue of $307 million, Forbes reported.
Jenner’s products were only sold online when it was first launched, but in 2018 the brand struck a deal to sell its goods in 1,100 Ulta Beauty stores.
In 2019, Jenner expanded her empire with Kylie Skin, a line of moisturizers, under-eye creams and facial scrubs.
In 2019, the privately held Kylie Cosmetics was worth around $900 million, according to estimates by Forbes.
However, in November 2019, news broke that Jenner would be selling a stake of her beauty business to CoverGirl owner Coty, in a deal that is said to value to the reality TV star’s company at about $1.2 billion. Earlier this month, Coty announced that Christoph Honnefelder would become Kylie Cosmetics' new CEO.
Coty said it will pay $600 million for a 51 percent stake in the company.
The Associated Press contributed to this report.