BackgroundEngaging people in advance care planning is a challenging systemic problem that requires a social innovation approach and a conceptual framework to guide behavioural and social change efforts.AimTo identify stakeholders' perspectives on barriers to advance care planning engagement, options for overcoming these barriers, and user needs. The findings will inform the design of a health behaviour change intervention for engaging older adults (50+) in advance care planning.DesignTo advance co‐production and intervention design goals, the study used collective intelligence and scenario‐based design methods.MethodsFollowing a systematic stakeholder analysis, 22 participants were recruited to three online collective intelligence sessions. The socioecological perspective informed framing of integrated findings and specifying factors at the individual, interpersonal, service, and system levels.ResultsIdentified barriers (n = 109) were grouped into seven categories: (i) Psychological, (ii) Advance Care Planning Literacy, (iii) Interpersonal and Interprofessional, (iv) Service‐Related, (v) Resources and Supports, (vi) Advance Care Planning Process and Methods, (vii) Cultural and Societal. Stakeholders generated 222 options for overcoming these barriers and specified 230 service user needs. The need to change perceptions of advance care planning, increase psychological readiness, and target advance care planning literacy was highlighted (individual‐level). Timely, focused, and meaningful interaction between the key ACP actors must be facilitated using creative strategies (interpersonal‐level). Need‐ and value‐based services, including high quality resources, support systems, and infrastructure, should be co‐designed (service‐level). Cultural and societal transformation is required (system‐level).ConclusionFindings integration offered insight into the complexity of the design context and problem situation and identified directions for context‐specific advance care planning intervention development. The use of design thinking methodologies is recommended for the next phase of complex intervention development.ImplicationsThe study presents a roadmap of actions required from policy‐makers, practitioners, and researchers to ensure the design of adequate advance care planning interventions.Reporting MethodQuality of reporting was assured by adherence to Consolidated Criteria for Reporting Qualitative Research (COREQ) guidelines (International Journal for Quality in Health Care, 19, 2007, 349).Patient or Public ContributionPatient and public representatives participated in the collective intelligence sessions. Members of the All Ireland Institute of Hospice and Palliative Care Voices4Care facilitated that process. Findings from the first CI session (involving patients and caregivers) informed the content, format, and methods used in subsequent CI sessions.