In this research, a cross-sectional quantitative survey was conducted on a convenience sample of working adults (N = 550) from different race, gender, age, qualification, job level and tenure groups in various South African organisations, with the intention of developing a psychosocial model of career wellbeing for the working adult in the South African context. To identify the elements and nature of the model, the relationship dynamics between the constructs of occupational passion, psychological career resources, psychosocial career preoccupations and the outcome of career satisfaction were examined. The mediating effect of psychological career resources and psychosocial career preoccupations on the relationship dynamics between occupational passion and career satisfaction was determined. The moderating effect of certain sociodemographic variables (race, gender, age, qualification, job level, and tenure) on the relationship dynamics between the research constructs was measured. In addition, an evaluation of the differences manifested by individuals from various sociodemographic backgrounds (race, gender, age, qualification, job level, and tenure) regarding the research constructs added to an understanding of the manifested model. Correlation and inferential statistical analyses (multi-level mediation modelling, regression analysis and tests for significant mean differences) indicated that career management practices should consider harmonious passion to be an important intrinsic motivational antecedent in explaining the variance in individuals’ career satisfaction as it can facilitate the development of important psychosocial resources. These resources include flexible career preferences, well-crafted career plans and actions to achieve career goals, career harmonisers (i.e. self-esteem, behavioural adaptability and emotional literacy) and a strong need to be upskilled and employable (career adaptation needs). These elements manifested as the core elements of the psychosocial career wellbeing profile. Job level and race were further indicated as important sociodemographic variables in explaining levels of career satisfaction. Differences between race, gender, age, qualification, job level and tenure groups, for the constructs of occupational passion, psychological career resources, psychosocial career preoccupations and career satisfaction, also need to be considered in the career wellbeing profile. Theoretically, the results advanced career theory by empirically validating the core elements of the career wellbeing profile. These may be applied to inform career management practices and consequently enhance the career wellbeing of working adults. / Industrial and Organisational Psychology / Ph. D. (Psychology (Industrial and Organisational Psychology))