Kylie Jenner — Kylie Cosmetics ($900 Million)

Yes, she was born a Kardashian-Jenner — but Forbes (controversially) named her the youngest "self-made" billionaire in 2019 at 21. Kylie Lip Kits sold out in 30 seconds. She built Kylie Cosmetics with a team of seven people and sold 51% to Coty for $600 million. Annual revenue hit $360 million in 18 months. Forbes later revised her billionaire status downward, citing inflated financials. The "self-made" debate will never end, but the business execution — $600 million exit before 23 with almost no employees — is undeniable regardless of your last name.