Can a convicted felon in the United States travel to Canada? According to several legal sources and the Canadian government: it is possible, but the process is difficult and it takes time to get approval.
In general, most convicted felons can't travel to Canada. However, if your conviction was a long time ago, you may be able to apply for the proper paperwork that will let you enter Canada.
You can learn more about this here:
Application for Rehabilitation for Persons Who are Inadmissible to Canada Because of Past Criminal Activity
Rehabilitation For Persons Who Are Inadmissible to Canada Because of Past Criminal Activity
You can apply for individual rehabilitation if at least five years have passed since you completed your criminal sentences. People who are ineligible for approval of rehabilitation because not enough time has passed can complete the form and check “For Information Only.” An officer will decide if special permission for temporary admission is warranted.