Bill Gates (left) and Warren Buffett.Bill Gates/YouTube Warren Buffett and Bill Gates first met on Fourth of July weekend in 1991. The investing icon and the Microsoft cofounder doubted they would have much in common. Buffett and Gates went on to become close friends and philanthropic partners. See more stories on Insider's business page. Warren Buffett and Bill Gates are very close friends who have partnered in philanthropy, political activism, and online bridge.