This research has examined the role that motivation, the satisfaction of the basic needs of autonomy, competence and relatedness, and individual and societal-level factors play in the construction of workplace well-being among European project staff. This study specifically addressed staff working to deliver European-funded projects in the fields of education, training, youth and sport. This research has drawn on Self-Determination Theory, and its sub-theories, Organismic Integration Theory (OIT) and Basic Needs Theory (BNT), as well as literature on Subjective Well-being (SWB) as the theoretical lens through which to examine this topic. To organise this research, three central research questions were developed, which have provided the anchor around which the research has been designed, actioned, analysed and presented. To sufficiently answer these research questions, an explanatory sequential research design was followed: commencing with a quantitative survey, with this quantitative data later enriched through two online focus group sessions. Through this process, survey data was collected from 109 participants who answered existing scales to measure the relationship between work motivation, basic need satisfaction at work and subjective well-being measured in this study through assessing life satisfaction. This survey was composed of the following scales: Work Extrinsic and Intrinsic Motivation Scale (WEIMS), Basic Psychological Needs at Work Scale (BPNS) and Satisfaction with Life Scale (SWLS). Data analysed from these scales identified positive correlations between intrinsic and identified forms of motivation and life satisfaction, negative associations with amotivation and life satisfaction, and also found that autonomy had the strongest correlation with life satisfaction, followed by competence and relatedness. Qualitative data from the two online focus groups were analysed through Reflexive Thematic Analysis, resulting in the development of five themes: the burden of competence, organisational disconnect, personal responsibility for well-being, the flexibility and paradox of telework and the influence of culture and family values on work values. Integrated analysis highlighted that while the satisfaction of basic needs supports well-being, competence can become a source of stress when it leads to additional or unfair workloads, and autonomy can also lead to over-work and a sense of disconnection when not backed by structural and relational supports. This research also highlighted the complex interaction between individual motivation and organisational context. While levels of integrated motivation were high according to the WEIMS data, in the qualitative data, it became apparent that in unsupportive work environments, where workload is uneven and structural supports are lacking, even highly motivated staff may negatively construct their workplace well-being in these environments. These insights contribute to theoretical understanding of well-being in high pressure project-based work environments, offering insights for policy and practice.