Background <p>Despite comprising over 70% of the global healthcare workforce, women remain significantly underrepresented in healthcare leadership. This imbalance has implications for care quality, as leadership diversity is increasingly recognised as a determinant of care quality, equitable outcomes, and health system performance. Structural barriers persist across academic medicine, health services, and professional organisations, limiting career progression and leadership opportunities for women. Existing efforts have largely prioritised individual-level interventions, with limited attention to the systems- and organisational-level determinants that influence adoption, implementation, and sustainability of gender equity initiatives. Coordinated action is needed to address gender inequality through sustainable, evidence-informed systems change.</p> Methods <p>This protocol outlines the Organisational Change Management workstream within the Australian Advancing Women in Healthcare Leadership initiative, a nationally implemented, multi-sector partnership. Using a mixed-methods, co-produced implementation research approach, the workstream will implement and evaluate multi-level interventions and associated implementation strategies across system and organisational levels. Guided by the Consolidated Framework for Implementation Research, the Learning Health System framework, and the Reach, Effectiveness, Adoption, Implementation and Maintenance evaluation model, stakeholders are engaged across outer (policy, regulation, funding) and inner (organisational culture, leadership structures) settings. Data collection includes administrative datasets and policy documents, semi-structured interviews, and surveys. Qualitative data will be analysed thematically and quantitative data analysed descriptively. Findings will be triangulated to inform the selection, tailoring, and evaluation of implementation strategies and a codesigned implementation toolkit, supported by iterative learning cycles.</p> Discussion <p>This protocol describes a national initiative applying a systems- and organisational-level, co-produced approach to advancing gender equality in healthcare leadership, engaging health services, professional colleges and associations, government, and women in the workforce. By leveraging implementation science and systems change methodologies, the initiative aims to support sustainable organisational transformation. The protocol provides a replicable framework for advancing gender equality in healthcare leadership and beyond and contributes to implementation science by demonstrating how multiple established frameworks can be integrated to operationalise large-scale, system-level organisational change in complex healthcare systems.</p>