The withdrawn charge stemmed from an early-morning incident late last December, when Bieber and five other people were picked up by a limousine from a Toronto nightclub.
Police alleged Bieber, 20, hit the limo driver several times in the back of the head.
Prosecutors said the charges were withdrawn because there was no reasonable prospect of conviction.
Bieber is due back in soon to fight new charges. His Toronto lawyer said last week that Bieber had been arrested for dangerous driving and assault following a collision between a minivan and an ATV that led to a physical altercation involving a photographer.