Many people do not realize that a DUI or other misdemeanor conviction in the United States can bar you from entering Canada. Folks who head to Canada on vacation are sometimes turned away at the border because a member the family has a DUI conviction. People on business trips, or hunting and fishing trips face the same problem.
If you have a conviction for DUI, operating after license suspension, leaving the scene of an accident, dangerous driving or many other misdemeanor charges, you are “inadmissible” under Canadian immigration law. If that is your only criminal conviction in your life you are inadmissible for 10 years. After that you are deemed rehabilitated.
If you have two or more convictions you must apply for rehabilitation with the Canadian government. It is a pretty involved process that requires you to submit a lot of documents and a fee. Processing takes up to a year. You cannot apply for rehabilitation until five years after the last action flowing from the second conviction.