Drawing on case studies of three incarcerated trans women's legal challenges to secure their placement in women's prisons, this dissertation examines how trans rights are articulated and applied within the cisgenderist, colonial confines of Canadian prisons. Findings serve to demystify Canada's guise of gender exceptionalism that emerges through trans rights protections and discourses by grounding the introduction of trans prison reforms within the context of gendered colonialism. While overturning the genital-based definition of gender in prisons, trans prison policies are haunted by Western bio-essentialist logics that they sought to replace. What has resulted is new constructions of trans women as potential risks -as sexual, institutional, and psychological threats to cis women and to the institution -to justify their regulation in, and exclusion from, women's prisons. Meanwhile, a superficial gesture to the inclusion of Two-Spirit people within these policies transforms sovereign Indigenous ways of being into "gender minorities" in Western eyes, which is a potentially colonizing reduction that exists in tension with Indigenous resurgence movements. While at once exemplifying the limits and potential colonial harms associated with liberal trans recognition in prisons, this research also reveals how trans prison policies effect more than the conditions of confinement. When taken up in legal battles against extradition and at the point of sentencing, the rights of incarcerated trans people may be seen as tools to challenge and resist penal power in ways that align with anti-colonial and abolitionist efforts. This dissertation concludes with a theory of gender self-determination as a collective struggle for freedom from the oppressive and colonial grasp of gender. By establishing prison abolition and Indigenous self-determination as foundational tenets of this vision of freedom, this research contributes to the call for settler trans political organizing to move beyond rightsbased pursuits and align their movements with Indigenous decolonizing efforts in all their forms.