Background Life-course socioeconomic factors may have a role in dementia aetiology but there is a current paucity of studies. Meta-analyses of individual participant data would considerably strengthen this evidence base. Aims To examine the association between socioeconomic status in early life and adulthood with later dementia death. Method Individual participant meta-analysis of 11 prospective cohort studies (1994-2004, n = 86 508). Results Leaving full-time education at an earlier age was associated with an increased risk of dementia death in women (fully adjusted hazard ratio (HR) for age ⩽14 v. age ⩾16: HR = 1.76, 95% CI 1.23-2.53) but not men. Occupational social class was not statistically significantly associated with dementia death in men or women. Conclusions Lower educational attainment in women was associated with an increased risk of dementia-related death independently of common risk behaviours and comorbidities