Yes, today is Thanksgiving Monday in Canada. It is a statutory holiday across the country. Government offices, banks, and most businesses are not open today. That includes Toronto and Ottawa. Retailers are a mixed picture, so call ahead before you go out.
In the United States, today is Columbus Day, also a federal holiday. Some states recognize it as Indigenous Peoples Day. U.S. stock markets and many banks are open today, but hours may be shorter than normal.