Most incarcerated women in Canada are mothers. Because women are the fastest growing population in carceral facilities, protecting the rights of incarcerated women to breastfeed their children is increasingly important. There is considerable evidence that incarcerated women in Canada experience poor physical and mental health, isolation, and barriers to care. Incarcerated women and their children could benefit significantly from breastfeeding. This Insight in Policy explores policy and legal protection for breastfeeding in Canada as it relates to carceral facilities, considers key cases regarding breastfeeding rights among incarcerated women, and presents recommendations for policy development and advocacy. The Canadian Constitution and human rights legislation across Canada prohibits discrimination on the basis of gender and includes pregnancy and the possibility of becoming pregnant as a characteristic of gender. Some provinces note that breastfeeding is a characteristic of gender. Women's Wellness Within, a nonprofit organization providing volunteer perinatal support to criminalized women in Nova Scotia, conducted a scan of all provincial and territorial correctional services acts and the federal Corrections and Conditional Release Act: none mention breastfeeding. Protocols for breastfeeding during arrest and lockup by police were not available in any jurisdiction across Canada. International law, including the Convention on the Rights of the Child, the Nelson Mandela Rules, and the Bangkok Rules, have application to the rights of incarcerated breastfeeding women. The Inglis v. British Columbia (Minister of Public Safety) (2013) and Hidalgo v. New Mexico Department of Corrections (2017) decisions are pivotal examples of successful litigation brought forward by incarcerated mothers to advance breastfeeding rights. Improved application and understanding of existent law could advance breastfeeding rights.