25. Ayman Hariri

Net Worth: $1.4 B
Age: 45
Residence: France
Nationality: Lebanese
Industry: Construction & Engineering

Ayman Hariri is a son of the late Rafik Hariri, Lebanon's prime minister, who was assassinated while in office in 2005. He inherited a stake in his father's Saudi-based construction company, Saudi Oger, and sold it to his brother Saad in 2014. In 2017, he sold his 42% stake in family holding company GroupeMed for $535 million. He invests in startups through New York-based firm Red Sea Ventures; among its investments was the smart thermostat Nest, now part of Google. He's a cofounder and CEO of Vero, an ad-free social media platform that lets users share music, videos and photos.