Background: Nurses transitioning into first-line nurse manager (FLNM) roles often receive unclear expectations, limited support, and inadequate preparation.These gaps raise concerns about regulatory readiness, as leadership competence underpins workforce stability and care quality.Experience-based co-design (EBCD) engages stakeholders to create relevant, context-sensitive programs.Purpose: To co-design a comprehensive educational program that supports novice FLNMs by addressing both technical competencies and emotional preparedness based on stakeholder input and contextual realities in two divisions of a highly specialized tertiary hospital.Methods: This study implemented a co-design process using the EBCD approach guided by the Medical Research Council Framework for complex interventions.Data collection included nonparticipant observation, seven focus groups, and two semi-structured interviews.Insights informed a persona archetype and journey map, which were the central tools used in four co-design workshops.Participants collaboratively identified priorities, which directly informed the content and structure of the intervention. Results:Participants in Stages 2 and 3 of the EBCD process included FLNMs (n = 26), nursing directors (n = 5), chief nursing officers (n = 2), and bedside nurses (n = 25).The co-design process generated a structured program comprising an onboarding phase and a multicomponent module-based curriculum.Validation workshops confirmed relevance, adaptability, and alignment with organizational and regulatory standards.A phased implementation plan and evaluation based on the RE-AIM (Reach, Effectiveness, Adoption, Implementation, Maintenance) Framework were endorsed to guide sustainability and scalability.Conclusion: Integrating EBCD with the Medical Research Council Framework produced a feasible, contextually grounded intervention.The program enhances regulatory readiness by combining technical, emotional, and relational preparation, offering a transferable model for leadership J o u r n a l P r e -p r o o f development.This study provides a replicable framework for transition programs to support novice FLNMs and strengthen workforce capacity in alignment with regulatory standards.