Health policy and systems research (HPSR) is increasingly being funded and conducted worldwide. There are currently no specific guidelines or criteria for the ethical review and conduct of HPSR. Academic debates on HPSR ethics in the scholarly literature can inform the development of guidelines. Yet there is a deficiency of academic bioethics work relating to justice in HPSR. This gap is especially problematic for a field like HPSR, which can entail studies that intervene in ways affecting the social and health system delivery structures of society. In this paper, we call for interpreting the principle of justice in a more expansive way in developing and reviewing HPSR studies (relative to biomedical research). The principle requires advancing health equity and social justice at population or systems levels. Drawing on the rich justice literature from political philosophy and public health ethics, we propose a set of essential justice considerations to uphold this principle. These considerations are relevant for research funders, researchers, research ethics committees, policymakers, community organisations and others who are active in the HPSR field.