The current study had two main aims: (1) to examine the combined and specific associations between various lifestyle factors (eg, education, occupational attainment, physical activity, leisure activities, social engagement, diet, and mindfulness) and cognitive reserve, defined as residual variance in cognition after accounting for brain imaging variables, in a community‐based sample of older adults without dementia; and (2) to explore whether these associations differed by APOE ε4 carrier status, given its link to increased cognitive decline risk. Here, APOE is linked to Mental deterioration.