Background: Dementia is now Australia’s leading cause of death in females, with women from multicultural backgrounds disproportionately affected. In the absence of a treatment, there is an urgent need for culturally tailored, gender-responsive dementia risk-reduction education. However, few programs have been co-designed with multicultural communities, and none have focused specifically on women. Objective: To co-design a sustainable dementia risk-reduction program with Arabic-, Greek-, Hindi-, Punjabi-, Swahili-, and Vietnamese-speaking women across Australia. Methods: A participatory co-design approach was used, guided by dementia risk-reduction evidence including the Lancet Commission. Data sources included expert interviews with Australian and international dementia prevention specialists and co-design workshops with multicultural women. Six initial workshops explored knowledge, beliefs, and content needs, informing a draft English program. A further six in-language workshops refined cultural adaptation. Data from field notes, artefacts, and audio-recordings were thematically analysed. Results: Eighty-six women participated across 12 workshops nationwide. Key findings included strong acceptance of prevention framed around women’s wellbeing; preference for bilingual delivery, simple visuals, and culturally and faith-aligned examples; and demand for practical, low-cost strategies including physical activity, diet, social connection, and cardiovascular health. Trusted community venues, peer educators, and flexible delivery were key enablers. These insights informed initial prototypes including modular slide decks, facilitator guides, take-home action sheets, and referral pathways. Conclusion: Co-designing with multicultural women ensured the program was pragmatic, and responsive to the specific cultural, linguistic, and health priorities of the targeted women groups. The MindCare4Women program offers a promising model for developing culturally responsive health programs that address inequities across Australia’s multicultural women.