The Oracle of Omaha is a nickname for Warren Buffett, who is arguably one of the greatest investors of all time. Buffett is the chair and CEO of Berkshire Hathaway, a company that he became the controlling shareholder of in the mid-1960s. He is called the Oracle of Omaha because the investment community very closely follows his investment picks and comments on the market, and he lives and works in Omaha, Nebraska.