This study examined the association between childhood stress and late-life health and dementia in Aboriginal Australians from urban and rural communities. Participants completed a life course survey of health, well-being, cognition, and social history which included the Childhood Trauma Questionnaire (CTQ) which measures physical, sexual and emotional abuse and physical and emotional neglect. Childhood stress appears to have a significant impact on emotional health and dementia for older Aboriginal Australians. Higher CTQ scores were associated with depression, anxiety, suicide attempts, dementia diagnosis, and, specifically, Alzheimer's disease. The ongoing effects of childhood stress needs to be recognised as people age, particularly in relation to dementia prevention and care, as well as in populations with greater exposure to childhood adversity, such as Aboriginal Australians. This research adds to a growing body of evidence suggesting adverse early life experiences, including abuse and neglect, increases the risk of dementia in older age.