Can parents be held responsible for damage or criminal activity that their children commit?

Parental Responsibility Act of Ontario

Yes. The Parental Responsibility Act, 2000 holds parents and guardians civilly liable for damages or losses incurred at the hands of their children.

As a parent or guardian of a child (under 18yrs) you should familiarize yourself with this short statute that can have a profound effect on your finances if you fail to exercise adequate supervision and control over your children.