O'Malley told reporters the obscenity charge had "absolutely nothing to do with any ‘kiddie porn' allegations."
The plea in federal court in Akron, Ohio, capped nearly four years of speculation after FBI agents raided O'Malley's Chagrin Falls home and seized two computers. A search warrant revealed that the agents were looking for images of child pornography and records related to a billboard deal that involved the city of Cleveland and was brokered by O'Malley.
O'Malley's lawyer, Ian Friedman, declined to give details on the computer images that led to O'Malley's guilty plea, but he said they did not include child pornography.
The charges state that between Feb. 18, 1998, and Nov. 10, 2004, O'Malley used an AOL account "for the carriage in interstate and foreign commerce of numerous obscene, lewd, lascivious and filthy pictures, writings and other matters of indecent character."
O'Malley faces up to five years in prison on the felony charge.
O'Malley is scheduled to be sentenced in August. According to the plea agreement, he is likely to face at least six months of prison under federal sentencing guidelines but could get probation or be put under house arrest.
He is free on $100,000 bond.