This article examines the race-thinking and colonial reasoning circulating in two recent developments in Canadian law with respect to polygamous marriage: the Polygamy Reference that upheld the Criminal Code provision on polygamy and the Zero Tolerance for Barbaric Cultural Practices Act. This legislation introduced changes to Canada’s immigration regulations, which include the practice of polygamy as a basis for refusing foreign applicants and deporting foreign nationals. I address how insights from the field of evolutionary psychology were applied in the Polygamy (...) Reference and what discursive and material resonances they had in the Zero Tolerance Act. Drawing on the work of Sylvia Wynter, I situate these judicial and legal developments in relation to violence, within colonial formations of state power, and as forces supporting white supremacy through the continuing valorization of monogamy as a foundational aspect of social and sexual citizenship in Canada. (shrink)