In 2026, an estimated 446,500 Australians are living with dementia, and that number is estimated to rise to over one million by 2065.[1] Dementia is often misunderstood as an inevitable part of ageing, yet the 2024 Lancet Commission identified 14 modifiable risk factors and that acting on them across the life course could prevent or delay up to ~45% of dementia cases.[2] Despite this, dementia is largely absent from public and preventive health strategies in Australia. Dementia Australia is calling for a life course approach to brain health and dementia prevention, recognising that dementia risk is shaped by exposures and protections from early life through mid and later life. Dementia risk is not evenly distributed across the population, with certain groups higher risk due to a greater prevalence of modifiable risk factors, driven by social determinants of health (for example education, income, housing and racism). Effective prevention requires sustained, population‑level efforts that support lifelong learning, cardiovascular and metabolic health, sensory health, physical activity and social connection, alongside action on the social determinants that drive differences in risk and access. This presentation will summarise the evidence for a life‑course brain health approach and outline practical policy implications for decision‑makers and public health practitioners to minimise risk and delay onset and progression. References: 1. Australian Institute of Health and Welfare, Dementia in Australia. 2025, Australian Government. 2. Livingston, G., et al., Dementia prevention, intervention, and care: 2024 report of the Lancet Standing Commission. The Lancet, 2024. 404(10452): p. 572-628.