In the current article, we build on research from vocational psychology, multicultural psychology, intersectionality, and the sociology of work to construct an empirically testable Psychology of Working Theory (PWT). Our central aim is to explain the work experiences of all individuals, but particularly people near or in poverty, people who face discrimination and marginalization in their lives, and people facing challenging work-based transitions for which contextual factors are often the primary drivers of the ability to secure decent work. The concept of decent work is defined and positioned as the central variable within the theory. A series of propositions is offered concerning (a) contextual predictors of securing decent work, (b) psychological and economic mediators and moderators of these relations, and (c) outcomes of securing decent work. Recommendations are suggested for researchers seeking to use the theory and practical implications are offered concerning counseling, advocacy, and public policy.