Augustine "Og" Mandino II (December 12, 1923 - September 3, 1996) was an American author. He wrote the bestselling book The Greatest Salesman in the World. His books have sold over 50 million copies and have been translated into over twenty-five different languages. He was the president of Success Unlimited magazine until 1976 and is an inductee of the National Speakers Association's Hall of Fame.