In general, temporary residents and applicants applying for permanent residence are considered to be criminally inadmissible if the person was convicted of an offence in Canada; was convicted of an offence outside of Canada that is considered a crime in Canada; or committed an act outside of Canada that is considered a crime under the laws of the country where it occurred and would be punishable under Canadian law.
Convictions / offences outside Canada
If you were convicted of or committed a criminal offence outside Canada, you may overcome criminal inadmissibility by applying for rehabilitation, or you may be deemed to have been rehabilitated if at least ten years have passed since you completed the sentence concluded.
If the offence is one that would, in Canada, be prosecuted summarily, and if you were convicted for two (2) or more such offences, the period for rehabilitation is at least five (5) years after the sentences imposed concluded.
Convictions / offences in Canada
If you have a criminal conviction inside of Canada, you need a record suspension (pardon) from the Parole Board of Canada (PBC).
Basis of Eligibility
In addition to the requisite time periods above one needs to show genuine remorse for their action and demonstrated change in their life as well as a sufficiently important reason for moving or visiting Canada to outweigh the risks