Child marriage among Rohingya refugees living in Cox’s Bazar, Bangladesh, is driven by economic strain and deep-seated gender norms. Mounting evidence shows the harmful effects of child marriage, and SDG 5.3 underpins a global impetus to eliminate it. Our mixed-methods research across refugee camps in Ukhia and Teknaf Upazilas included quantitative surveys and qualitative interviews (IDIs) with married and unmarried girls and their parents, and focus group discussions (FGDs) with parents of married and unmarried girls, boys, and community members to understand Rohingya perspectives on child marriage, the role of norms in displacement, and how married girls’ capabilities are impacted by their marital status. We find that married girls face increased gender-based violence (GBV) risks, including intimate partner violence (IPV), and greater mental distress. While norms are shifting for older Rohingya women, married girls are excluded from social participation or personal growth beyond the household. We argue that involving married girls in community activities and vocational training designed according to local market needs may empower married girls.