It is a big surprise to many Americans, but yes, you are at risk of being denied entry to Canada if you have a dui or a criminal record. Drunk driving in Canada is a serious offense. Any conviction under the Canadian legislation will cause criminal inadmissibility to Canada. However, you may overcome this inadmissibility by requesting a Temporary Resident Permit (TRP) prior to your trip, or, if eligible, you may also apply for Criminal Rehabilitation.