O'Malley, a Democrat, was the 222nd voter to cast a ballot in the primary at the Public Safety Training Facility in Baltimore on Friday afternoon, the first day of early voting in Maryland.
Former Gov. Robert Ehrlich, O'Malley's likely opponent in November, also is encouraging people to vote early, even though he's been critical of early voting and vetoed legislation to create it when he was governor.
Ehrlich said it's now the law in the state and he's going to live with it and, it is hoped, take advantage of it. Andy Barth, an Ehrlich campaign spokesman, says Ehrlich is expected to take part in early voting next week.