Scholarship focusing on how international research can contribute to justice in global health has primarily explored requirements for the conduct of clinical trials. Yet health systems research in low- and middle-income countries (LMICs) has increasingly been identified as vital to the reduction of health disparities between and within countries. This paper expands an existing ethical framework based on the health capability paradigm – research for health justice – to externally-funded health systems research in LMICs. It argues that a specific form of health systems research in LMICs is required if the enterprise is to advance global health equity. “Research for health justice” requirements for priority setting, research capacity strengthening, and post-study benefits in health systems research are derived in light of the field's distinctive characteristics. Specific obligations are established for external research actors, including governments, funders, sponsors, and investigators. How these framework requirements differ from those for international clinical research is discussed.