The Asia Pacific Region's middle-income countries (MICs) face unique challenges in the ongoing development of primary care (PC) systems. This development is complicated by systemic factors, including rapid policy changes and the introduction of private healthcare services, as well as the mounting challenges associated with ageing populations and increasing rates of chronic diseases. Despite the widespread acknowledgement of the importance of family doctors in the development of PC services, relatively little is known about how these roles have developed in Asian MICs. To address this gap, this systematic review presents a synthesis of recent research focused on the role of family doctors within the PC systems of MICs in the Asia Pacific Region. We searched six electronic databases (CINAHL Complete, Embase, PsycINFO, PubMed, Web of Science, and Index Medicus for the South-East Asia Region and Western Pacific) for peer-reviewed qualitative literature published between January 2010 and December 2020. The quality of the studies was evaluated using the Critical Appraisal Skills Programme tool. Eighteen articles were included in the analysis. Findings from these articles were extracted and synthesised using qualitative thematic synthesis. We used the Rainbow Framework to analyse the interconnections within health systems at the macro, meso and micro levels. Our analysis of the included articles showed that family doctors play a crucial role in bridging the gap between hospitals and communities. They are essential in adopting holistic approaches to health and wellbeing and are in a unique position to try and address social, psychological, and biological aspects of health. Our findings also highlight the influence of policy changes at the macro level on the role and responsibilities of family doctors at the meso (organisational) and micro (interpersonal) levels. Limited research has explored the role of family doctors in the ongoing development of primary care systems in MICs in the Asia Pacific Region. The findings of this review have significant implications for policymakers and healthcare administrators involved in ongoing improvements to and strengthening of PC systems. Areas of particular concern relate to policy linked with training and workforce development, insurance systems and public awareness of what primary care services are.