Public voices have largely been absent from the discussions about open access publishing in medical research. Yet the public have a strong interest in ensuring open access of medical research findings because of their roles as funders, advocates, research participants, and patients. By limiting access to research outputs, the current publishing system makes it more difficult for research to be held accountable to the public. Paywalls undermine the work of public advocacy, which requires open access in order to lobby for policy changes and research funding. Research participants generously give their time and energy to research studies with the assumption that the results will be broadly disseminated. Finally, members of the public have a stake in open access publishing as a resource for health information and decision-making. This commentary explores these crucial roles of the public in order to develop a public rationale for open access medical research. We outline a critique of the current academic publishing ecosystem, re-focus the open access debate from a public perspective, and respond to some of the arguments against public open access. Although open access to medical research is not a panacea, removing paywalls and other barriers to public access is essential. The public are critical stakeholders of medical research data.