Yes, today is Thanksgiving Monday in Canada. It is a national public holiday. Government offices, banks, and most businesses are not open today. That includes Toronto and Ottawa. Retailers are open on varying schedules, so call ahead before you go out.
In the United States, today is Columbus Day, also a federal holiday. Some states mark it as Indigenous Peoples Day instead. U.S. stock markets and many banks are open today, but hours may be reduced.