Facebook (FB) founder and CEO Mark Zuckerberg, 31, and Priscilla Chan, 30, are the youngest couple on this list.
They met at Harvard and were married in 2012, a day after his social media company began trading on Wall Street.
In 2010, Zuckerberg signed the Giving Pledge, committing to give away the majority of his wealth to philanthropic causes.
Related: Mark Zuckerberg in 90 seconds
In 2014, Zuckerberg and Chan announced they would donate $25 million to the Centers for Disease Control Foundation to combat Ebola.
