Kylie Jenner, a member of the Kardashian-Jenner family, is the youngest billionaire in history. (Forbes qualifies her as self made despite her family's already considerable wealth.) She owns 100% of her company, Kylie Cosmetics, which was most recently valued at $900 million.
Net worth: $1 billion
Age: 21
Citizenship: United States
Industry: Consumer Goods
Source of wealth: Self made, Kylie Cosmetics
Source: Forbes