Bieber's reps did not immediately respond to the Los Angeles Times' requests for comment.
The 21-year-old received an "absolute discharge" on the assault charge and only has to pay a $750 fine for the careless driving charge, the Toronto Star said. He faces neither jail time nor probation.
A judge warned the pop star that the lesson in this case was to "think before you act in the future."
"Everybody in life, no matter who they are, encounters difficult and disappointing and surprising situations," Justice Kathryn McKerlie said. "And part of maturing, of course, is to make sure that when you encounter those situations that you proceed calmly and think before you act."
Bieber was arrested in his native Canada last summer on suspicion of dangerous driving and assault after an ATV-minivan crash that police said turned physical, news reports said at the time.
The dangerous driving charge was later dropped.
His attorney, Brian Greenspan, told TMZ that no one was injured in the incident and that a photographer later pleaded guilty to trespassing.