Wearing a face mask in busy outdoor parts of Paris is mandatory from Monday morning as the country records a flare-up in COVID-19 cases.
Multiple streets, markets, as well as river banks and the famous hill of Montmartre are affected by the new decree.
The Paris town hall said in a statement that the measure was introduced because "the virus is again circulating more actively" in the Ile-de-France region with "nearly 400 people testing positive for COVID-19 every day."
"The rate of positive tests now stands at 2.4% in Ile-de-France against 1.6% on the national average," it also said, adding that "the incidence is particularly high in 20-30 year olds."
The measure applies to everyone over the age of 11 and is to last at least a month. The authorities stressed that the areas affected "are likely to change in the coming weeks depending on epidemiological data and observation of the use of public spaces."
Failure to comply will result in a €135 fine.
Several other French cities have already made masks mandatory in busy parts of their city centre including Lille, Nice, and Toulouse.
On Friday, health authorities reported 2,288 news cases - a sharp rise from the previous day 1,604 tally.
The General Health Directorate warned that "the indicators are deteriorating, confirming a more active circulation of the virus throughout the territory, especially in young adults".
France has recorded more than 30,300 COVID-19 deaths, making it the seventh most heavily impacted country in the world, according to a tally from Johns Hopkins University.