The 27-year-old singer lashed out at a crush of reporters outside London's Thames Magistrates' Court after he pleaded guilty to seven drug charges March 23.
Doherty admitted that he kicked BBC reporter Trudi Barber and knocked a microphone out of her hand before he sprinted away from reporters, jumped into his Jaguar and sped away.
The singer had pleaded innocent to assault, but changed his plea after watching television footage of the incident, his lawyer, Sean Curran, said.
Justice Helen Skinner also ordered Doherty to pay $475 in compensation and $380 in court costs.
Doherty, the on-off boyfriend of supermodel Kate Moss, appeared in court wearing a black coat and clutching a black trilby hat. He told the court he could not pay the fine Wednesday because he had only 50 cents with him.
He apologized for the incident, but called Barber part of the "harassing scum of press."
Skinner said Doherty was courting publicity outside the court by his "extravagant behavior."
"People in public life have a responsibility to behave and be a good role model to others," Skinner said. "Referring to the press as scum does no one any favors."
The troubled singer skirted a jail sentence on other drug charges in September when a judge ordered him to continue rehabilitation.