Recently, the role of social determinants of health on frailty and dementia has received increased attention. The aim of the present study is to explore the association of social determinants on cognitive impairment, frailty, and self-rated health. As health is influenced by many factors, we also examine other health determinants including lifestyle, health seeking behaviour, socio-demographics, and multimorbidity in the analysis. Cross-sectional analysis of the Healthy Older People Everyday (HOPE) study in Singapore was carried out on 998 older adults above the age of 65. We used forward stepwise multivariable logistic and linear regression analyses to assess the association of five health determinants (social determinants, lifestyle, health seeking behaviour, socio-demographics and multimorbidity) on frailty, cognitive impairment, and self-rated health. Mean age of participants was 71.1 ± 0.2 years; 154 (15.4%) were cognitively impaired; 430 (43.1%) were pre-frail or frail; mean self-rated health was 80.4 ± 15.6. Social determinants contributed between 29% to 57% of the overall variation found in the full model with all five health determinants adjusted for. Participants with higher education had significantly lower odds of cognitive impairment and frailty. Leisure physical activity was significantly associated with lower odds of frailty and cognitive impairment, and better self-rated health. Understanding the dynamics of different health determinants is crucial to protect the vulnerable in an ageing population. Our study highlights the need for a multidimensional, multidisciplinary and multisectoral approach in the prevention of frailty, cognitive impairment, and associated disability.