Polygamous marriages are not legal in Canada and are an offence under the criminal code.
Regulation 117(9)(c)(i) of the Immigration and Refugee Protection Regulations provides that a spouse is not a member of the family class if the spouse or sponsor was already married to another person at the time of the subsequent marriage. Canadian immigration law prohibits a second wife from being recognized as a spouse within the family class and provides that only the first marriage may be recognized for immigration purposes.
Recognizing First Marriage
For the first marriage to be recognized, the couple must live together in a monogamous marriage in Canada. Canadian common law imparts that a polygamous marriage can be converted into a monogamous marriage provided that the couple live together in a monogamous relationship from the time of arrival in Canada.
This can be demonstrated if the couple states their intention to convert their marriage to a monogamous one, followed by some factual evidence that they have complied.
In March 2014, a paper was prepared for the Admissibility Branch of Citizenship and Immigration Canada titled “Polygamy and Immigration.” Although it is now two years old, it is useful reading for anyone looking to familiarize themselves with this topic.
It was obtained through an Access to Information Act request, and I have embedded it below.Research Paper