Research ethics norms are primarily centered on respect for autonomy operationalized through informed consent. Significant ethical challenges can arise when conducting research with persons who have “cognitive impairments” that may limit their decisional autonomy. These challenges are additionally complex in research involving children with “cognitive impairments.” We outline dominant norms in pediatric research ethics, highlight current debates regarding these norms, and discuss considerations that arise when conducting research with ”cognitively impaired” children. Building on interdisciplinary research in childhood ethics, the authors argue for a shift in childhood research ethics norms toward participatory approaches anchored in the recognition of all children’s voices and agential capacities. Concrete strategies for recognizing agency in research with “cognitively impaired” children are shared. Rather than presenting a limitation for research with children, “cognitive impairment” affords opportunities to consider how to better recognize agency in research with all children.