Toronto police said Bieber, 19, hit a limousine driver several times in the back of the head.
The Canadian singer is due to appear in court in Toronto on March 10 charged with one count of assault.
Bieber arrived at a police station to a crush of media and screaming fans, emerging from a black SUV wearing a winter coat and a baseball cap. He spent about an hour and a half in the police station before leaving through a back exit.
Bieber's California-based lawyer Howard Weitzman said the singer was innocent and expected the assault case to be treated as a low-level summary offence, the equivalent of a misdemeanour in the United States. He said it was now a matter for the court to handle.
Jon Bollock, a 14-year-old fan waiting for Bieber to arrive outside the Toronto police station, said he wanted to see the singer but said: "It's pretty embarrassing for Canada.
In late December police investigated claims that a member of Bieber's entourage attacked a limo driver who was ferrying the star and several others. At the time police said it was unclear whether Bieber was involved.
Meanwhile Bieber has pleaded not guilty to drink-driving charges, resisting arrest and driving with an expired licence in Florida.
Court records show Bieber's lawyer filed the written plea in Miami-Dade County. Bieber already has an arraignment set for February 14, but Florida law does not require him to be present.
Defence lawyer Mark Shapiro said a decision on whether Bieber would attend has not been made.
Bieber and R&B singer Khalil Amir Sharieff were arrested last week in Miami Beach during what police described as an illegal street drag race between a Lamborghini and a Ferrari. Neither has been charged with drag racing.
Police say Bieber swore at an officer and admitted to smoking marijuana, drinking and taking a prescription medication.
Bieber also remains under investigation for felony vandalism in Los Angeles County over an egg-throwing episode that damaged his neighbour's home. Detectives searched his home on January 14 and prosecutors have sought additional information before determining whether to pursue charges.
The arrest and investigation, and now the Canada case, have brought Bieber more attention than the recent release of his latest album. Its reception has been far from the chart-topping success Bieber had after he debuted in 2009, with multiple platinum albums.
Last year Bieber made headlines for everything from clashing with a paparazzo and fainting at a show to being photographed smoking marijuana. German authorities charged him thousands of dollars after he abandoned a pet monkey that they seized from him for failing to have proper vaccination papers.
The singer also had to apologise to Bill Clinton after cursing the former US president and spraying his photo with cleaning fluid in a New York City restaurant kitchen.
Bieber was discovered through a YouTube video of him performing and his career has been guided by a pair of music industry heavyweights, singer Usher and manager Scooter Braun.
He has been nominated for two Grammy Awards for his 2010 full-length album debut My World 2.0, but his popularity has waned.
Braun tweeted today: "i ask people to be kind and hope for the best in people. not assume the worst. Thanks."