He won a lawsuit against the school for wrongfully firing him and was awarded $2.2 million plus interest.
O'Brien was fired by the Big Ten Conference school June 8, 2004. An NCAA ruling March 10, 2006, banned him from coaching by the NCAA for paying a recruit.
OSU attorneys appealed to the Supreme Court after an appeals court upheld the award.
Later, he won an appeal to reduce his punishment for an NCAA violation.
His tenure at Columbus lasted six years before he was fired by former Athletic director Andy Geiger for a $6,000 loan given to recruit Aleksander Radojevic from Serbia.
"I have felt all along that the penalty imposed upon me by the committee of infractions was both excessive and unjust," O'Brien said in a statement Jan. 31.