Evidence for the relation between personality and dementia risk comes mainly from American samples. We tested whether personality-dementia links extend to populations from England and Australia. Data from the English Longitudinal Study of Ageing (ELSA; N = 6,887; Follow-up mean: 5.64 years) and the Household, Income and Labour Dynamics in Australia (HILDA; N = 2,778; Follow-up mean: 10.96 years) were analyzed using Cox PH models. In both samples, higher neuroticism was associated with increased dementia risk. In ELSA, lower conscientiousness was related to increased risk. In HILDA, conscientiousness had a similar effect but did not reach statistical significance. The present work found a consistent association for neuroticism and suggests similar personality-dementia links across demographic groups and high-income countries.