Against the background of continuous transformation in global healthcare systems and the increasing complexity of nursing practice, the core competencies of registered nurses have attracted growing attention in nursing education, professional regulation, and workforce management. Clearly defining and systematically structuring nurse competencies is essential for ensuring safe, effective, and high-quality nursing care. Over the past two decades, a range of international organizations and national regulatory bodies have developed competency frameworks to articulate expectations for registered nurses across diverse clinical and organizational contexts. This review adopts an international perspective to synthesize and compare representative competency frameworks for registered nurses developed by the International Council of Nurses (ICN), the American Association of Colleges of Nursing (AACN), and the Nursing and Midwifery Council (NMC) in the United Kingdom. Key competency domains, structural characteristics, and underlying conceptual orientations of these frameworks are analyzed to identify areas of convergence and divergence. In addition, research on core competencies of registered nurses in China is reviewed, with particular attention to conceptual development, construction of evaluation instruments, and empirical applications in clinical and educational settings. The findings indicate substantial consistency across international competency frameworks in core domains such as clinical care, patient safety, communication and collaboration, and professional values. However, notable differences remain in the emphasis placed on leadership development, informatics, and digital competencies, and pathways for competency progression across career stages. International frameworks increasingly conceptualize competence as a dynamic and context-dependent construct, moving beyond static lists of skills toward integrated and developmental models of professional capability. Within the Chinese context, existing studies have largely focused on competency measurement and cross-sectional assessments, while research examining the structural relationships and developmental trajectories of nurse competencies remains limited. Emerging methodological approaches, including competency mapping and computer-assisted text analysis tools, offer new opportunities to integrate multidimensional competency elements and enhance the transparency of framework development. This review highlights the value of international comparison for informing the refinement of registered nurse competency frameworks and underscores the need for further research that combines international evidence with local healthcare contexts. The findings may provide a reference for advancing competency-based nursing education, improving regulatory standards, and supporting the sustainable development of the nursing workforce in China.