The 21-year-old TV personality and entrepreneur has made her fortune from her best-selling cosmetics business.
Her ranking has been confirmed by Forbes billionaires’ list.
The youngest Kardashian family member has achieved the milestone two years younger than Facebook founder Mark Zuckerberg, who was 23 when he cracked the 10-figure mark.
Jenner owns Kylie Cosmetics, the three-year-old beauty business that generated an estimated $360 million in sales last year.
“I didn’t expect anything,” she told Forbes Magazine.
“I did not foresee the future.
“But [the recognition] feels really good. That’s a nice pat on the back.
Amazon’s founder Jeff Bezos remains the world’s richest man, according to the list.
His fortune stands at $131 billion (£99.7bn), up $19bn (£14.5bn) from 2018.
Zuckerberg’s wealth is among those falling.
His personal fortune has dropped by $8.7bn (£6.6bn) in the past year to $62.3bn (£47.4bn), according to the Forbes list.
Microsoft founder Bill Gates sits at number two in the Forbes rankings, with his wealth swelling to $96.5bn (£73.5bn) from $90bn (£68.3bn) last year.
The number of self-made women reached 72 for the first time, up from 56 a year ago.