The number of older adults is growing rapidly in many countries throughout the world. For example, the number of Canadians aged 65+ is projected to increase by over 50% in the next 15 years. The burden of chronic disease rises swiftly with age, and although average life expectancies have increased, the number of healthy years lost to disability has increased as well. In combination, these age-related forces are projected to result in worse population health and increasing healthcare costs. Thus, identifying factors that contribute to healthy aging is vital for population health and containing rising healthcare costs. Most psychological, biomedical, and public health efforts have focused on reducing harmful risk factors (e.g., depression), and this approach has contributed greatly to prevention and treatment programs. However, expanding the focus to include upstream dimensions of psychological wellbeing (e.g., sense of purpose in life, optimism) may help inform the comprehensive, multidisciplinary, and multi-level response efforts needed to maximize healthy aging. A mounting body of evidence links higher psychological wellbeing with reduced risk of chronic diseases, yet, the mechanisms underlying these association are unclear. Without this understanding, a promising avenue of intervention cannot progress because we are unable to establish that psychological wellbeing plays a causal role in reducing risk of chronic conditions, or understand how intervening on psychological wellbeing might alter physical health outcomes. In this talk, I will describe a theoretical model for how psychological wellbeing may influence our physical health. I will then discuss results from a series of studies evaluating associations between psychological wellbeing and chronic conditions, and mechanistic biopsychosocial processes underlying these associations (e.g., preventive healthcare services and DNA methylation aging. Ultimately, our work aims to move the field forward by providing new directions for building a science of resilience and providing new targets for preventive and therapeutic interventions.