The ‘Open Science and Evidence-Informed Decision Making’ (EIDM) Learning Path is a targeted Train-the-Trainer Initiative, developed under the Skills4EOSC project, specifically designed for policymakers, civil servants, knowledge brokers and all stakeholders interested in Open Science and decision making. The learning path addresses the pressing need to equip these professional profiles with the knowledge, skills, and competences to engage with and apply Open Science principles in policy development and evidence-informed decision making. The programme aimed to improve policy effectiveness, transparency and trust by equipping participants with practical skills and knowledge. This training pathway is not a general-purpose curriculum but one tailored to the distinctive needs and roles of policy sector professionals. Recognising that little existing training material fully addressed these profiles, the development process combined a landscaping analysis of relevant initiatives with the creation of original, purpose-built content. The goal was to ensure that the training program responds directly to the real-world responsibilities, constraints, and opportunities faced by decision-makers and intermediaries in public administrations.