The Alfie star was pictured apparently lashing out at a female snapper as he tried to get to his car after leaving a London nightclub in July (09).
He was accused of striking Harsha Gopal on the head and slapping her face as she tried to take his picture, but denied the accusation - with his lawyer insisting the claims were "nonsense".
Law was adamant he had been blinded by cameras flashing and as he held his arm out he accidentally struck someone before apologising and leaving the scene.
Gopal reported the incident to police, but Law has now been told he will not face any charges.
In a statement, a spokesman for the Crown Prosecution Service says, "A careful analysis of the specific evidence in this case, which included photographs and eye witness statements, indicates that Mr Law had no intention to assault anyone.
"While Mr Law accepted that he may have come into contact with someone whilst attempting to make his way to his car, it is highly likely that a court would decide his actions were reasonable given that his path was deliberately impeded by a crowd of photographers."