Optimal mental health underpins full social participation. As people age, they confront personal and cultural challenges, the effects of which on mental health are not fully understood. The aim of this research was to learn from women of the Baby Boomer generation (born 1946–1964) what contributes to and hinders their mental health and wellbeing. Eighteen women participated in qualitative interviews (in English); data were analysed thematically. Participants were located across Australia in rural and urban areas; not all were born in Australia. They were diverse in education, employment status, and experiences of life and ageing. The women nominated as the main contributors to poor mental health in older women Illness and disability, Financial insecurity, Maltreatment, and Loss and grief. Contributors to good mental health were identified as Social interdependence, Feeling valued, Physical activity, Good nutrition, and Having faith or belief. Women’s accounts supplied other influences on mental health, both associated with the person (Personality and Intimate relationships and sex) and with society (Constructs of ageing, Gender, and Culture). Women also specified what they needed from others in order to improve their mental health as they aged: Public education about ageing, Purposeful roles for older women in society, Adequate services and resources, and Sensitive health care. In sum, older women wanted to be treated with respect and for their lives to have meaning. It is evident from these results that circumstances throughout life can have profound influences on women’s mental health in older age. Anti-discriminatory policies, informed and inclusive health care, and social structures that support and enhance the lives of girls and women at all ages will therefore benefit older women and increase the potential for their continuing contribution to society. These conclusions have implications for policy and practice in well-resourced countries.