Earnest Stanley O'Neal (born October 7, 1951) is an American business executive. He is the former President, Chief Executive Officer and Chairman of the Board of Merrill Lynch & Co. Inc., having served in numerous senior management positions at the company prior to this appointment. He has taken criticism for his performance during his reign as chief executive at Merrill Lynch, and the deterioration of the firm's stability and capital position. During the final hearings prior to the Bank of America merger, numerous people – including a founder's son, Win Smith – laid the blame on O'Neal for the firm's downfall and loss of independence.

E. Stanley O’Neal (* 7. Oktober 1951 in Roanoke, Alabama) war von 2002 bis 2007 Chief Executive Officer von Merrill Lynch.