Dementia is a public health and socioeconomic concern that is widely predicted to worsen as the proportion of older adults making up our global population increases.1 By 2050, 152 million people worldwide are expected to experience dementia, along with its associated impact. In an ambitious act to galvanise a global response, the 2013 G8 Dementia Summit was convened with a primary aim to identify a cure or disease-modifying therapy for dementia by 2025.2 New evidence has since deepened our understanding of the potential for disease-modifying therapies, making this target even more unrealistic. In parallel, rapidly accumulating evidence has emphasised the importance of broader societal policies for dementia prevention across the lifecourse.3 Here, we review the goals, progress, and challenges of the Summit activities, and propose potential ways forward to align policy with the public health evidence for dementia prevention.