The incident happened in Clova, Que., in a remote region 500 kilometres north of Montreal.
The girl was a passenger on the snowmobile. The vehicle ended up on top of her when the driver lost control.
Her family rushed her to the town of Parent, 100 kilometres southeast of Clova, near La Tuque.
Paramedics took over from there, transporting the girl to the hospital in La Tuque.
She was declared dead in hospital.
Investigators with the Sûreté du Québec arrived in Clova Sunday night and will try to understand the circumstances that led to the accident.