"Mental models" are deeply held internal images of how the world works. Often, we are not consciously aware of our mental models or the effects they have on behavior. Traditional mental models of jails include people, materials, and energy (especially emotional energy) and their flows. These mental models inspire practices like audits, chain of custody, and accountability as well as jail spaces designed to reduce stress and introduce normalcy. However, traditional mental models do not always address persistent jail-based challenges to safety, organization, and prosocial transformation. In March 2020, NIJ convened a virtual meeting of researchers and practitioners to explore the possibilities that arise from rethinking our view of jails. Participants discussed complementing traditional mental models by viewing jails as complex adaptive systems through the lens of complexity science, in which perception, cognition, and action continually interact and affect processes and outcomes. This article briefly introduces these concepts of complexity science relevant to jails and suggests areas for further research to help address persistent challenges in the field.