7. Cameron Johnson

Now 23, Johnson started his first business at the age of 9 and that was even before he graduated from high school. In less than a year, Cameron saved $50,000, which he preserved for his next project, My EZ Mail, which is an email forwarding company. It generated up to $3000 a month in advertising.

He then joined two other teens, Aaron Greenspan and Tom Kho, to create an online advertising company, Surfingprizes.com. During his freshman year of high school, which was at the age of 15, he used to receive cheques between $300,000 and $400,000 a month. Before graduating from high school, his combined assets were worth over $1 million.