INTRODUCTION: Healthcare organisations recognise the moral imperative to address inequalities in health outcomes but often lack an understanding of which types of interventions are likely to reduce them. This realist review will examine the existing evidence on the types of interventions or aspects of routine care in general practice that are likely to decrease or increase health inequalities (ie, inequality-generating interventions) across cardiovascular disease, cancer, diabetes and chronic obstructive pulmonary disease. METHODS AND ANALYSIS: Our realist review will follow Pawson's five iterative stages. We will start by developing an initial programme theory based on existing theories and discussions with stakeholders. To navigate the large volume of literature, we will access the primary studies through the identification of published systematic reviews of interventions delivered in general practice across the four key conditions. We will examine the primary studies included within each systematic review to identify those reporting on inequalities across PROGRESS-Plus categories. We will collect data on a range of clinical outcomes including prevention, diagnosis, follow-up and treatment. The data will be synthesised using a realist logic of analysis. The findings will be a description and explanation of the general practice interventions which are likely to increase or decrease inequalities across the major conditions. ETHICS AND DISSEMINATION: Ethics approval is not required because this study does not include any primary research. The findings will be integrated into a series of guiding principles and a toolkit for healthcare organisations to reduce health inequalities. Findings will be disseminated through peer-reviewed publications, conference presentations and user-friendly summaries. PROSPERO REGISTRATION NUMBER: CRD42020217871