The city councillor who spearheaded the law in Cote St-Luc says it is among the toughest in Canada.
Smoking is banned in indoor public spaces in Canada, but some municipalities have gone further to limit where people can puff away.
The new bylaw bans smoking within 20 metres of playgrounds and parks in Cote St-Luc, which is on the island of Montreal.
Councillor Steven Erdelyi, a father of two, said it often bothered him to have smokers nearby while his children played at the park.
The new bylaw encountered little opposition in the city of 31,000. It was the first municipality to ban smoking indoors before Quebec followed suit in 2006.
"I wouldn't say it's the strongest in Canada, but it's one of the strongest," Erdelyi said Tuesday.
The law will also ban smoking at events such as Canada festivities, which draw hundreds of people to public parks.
In Cote St-Luc, first-time offenders face a $50 fine while repeat offenders will be on the hook for $100.
But the city is hoping it won't need to use it, Erdelyi said.
Signs will be put up by the spring and a short grace period will follow to allow residents to understand the new rules.
"We're hoping that we won't have to enforce it by issuing fines,'' Erdelyi said. ''We're hoping just by putting up the signs, people will comply.
"When the provincial government introduced tobacco laws in Quebec, people were a bit hesitant at first but eventually complied."
The bylaw was passed unanimously by city council on Monday night.
According to anti-smoking lobby groups, similar bylaws exist in L'Ancienne-Lorette, near Quebec City.
City officials say they also found similar bylaws in Vancouver and in Prince Edward Island.