Sûreté du Quebec spokeswoman Sgt. Christine Coulombe said the incident happened around 12:20 p.m. on the Rang Petit Saint-Esprit.
According to Radio-Canada, the boy was biking home after visiting a friend.
He was not wearing a helmet at the time of the collision and Colombe said his injuries are considered life-threatening.
He is now in hospital in Montreal.
The woman driving the car was not injured in the collision and police investigators were interviewing her to determine what happened.
Colombe said alcohol was not a factor and Radio-Canada reports that it is not likely that she'll face criminal charges.
The road runs through countryside near the town of Nicolet and neighbours interviewed by Radio-Canada at the scene said cars often pass through at high speed.
The posted speed limit is 90 km/h.
"There are a lot of children who live along the road... and people don't slow down. It's scary," said one neighbour, who wasn't identified by Radio-Canada.
"I have three daughters who would take the school bus morning and night and you just had to cross your fingers," said Jean-Marie Leblanc, who also lives near the scene.