Just before 3 a.m. ET, a man frantically flagged down a patrol car in the city's north end and asked for help as his wife began to give birth in their car.
The officers helped the woman deliver her baby in the car near the corner of St-Laurent and Gouin boulevards in the Ahuntsic neighbourhood.
The 32-week-old boy was safely delivered and put into an ambulance with the mother.
A police escort brought the family to Sacré-Coeur Hospital.
Their four-year-old son was also in the car during the delivery.
Later in the morning. Const. Jean-Pierre Brabant brought stuffed bears for the boy and his newborn brother.
He said it is not common for police officers to have to deliver babies, but the officers on Christmas morning were more than happy to do so.
Both mother and baby are reportedly doing well.