The bylaw makes it illegal to own any dog the city deems a pit bull - loosely defined as American Staffordshire terriers, Staffordshire bull terriers, American pit bull terriers or any mix of these breeds.
Montreal mayor Denis Coderre has often cited public safety as the reason behind the legislation. Over the summer, a woman was attacked and killed by a dog, mistakenly identified as a pit bull.
"A city has the right to decide on its territory how to best protect it citizens," Coderre told reporters in October.
Additionally, the law gives current owners of so-called pit bulls until the end of March to provide the city with a criminal background check and pay $150 for a special permit. Their dog will have to be sterilized, vaccinated and microchipped - as well as muzzled and on a 4-foot leash at all times in public.