Jenner, 21, was finally given the title after months of speculation on Tuesday by Forbes as it unveiled its annual billionaires list.
At 21, she is both the youngest self-made billionaire and the youngest billionaire on Forbes’ ‘young billionaires’ list.
Jenner has amassed a personal net worth of $1billion through her wildly successful range of make-up, Kylie Cosmetics.
She overtakes Zuckerberg, who was 23 when he made his first billion 11 years ago in 2008.
Now, he is the eighth richest person in the world with a fortune of $62.3billion.