Person-Organisation (PO) Fit and authenticity play an important role in generating positive work attitudes such as job satisfaction, organisational commitment, organisational belonging and turnover intentions. However, the question remains: which is more important? Is one more closely related to these work attitudes? As such, this study explores the correlations of PO Fit and trait and state authenticity with job satisfaction, organisational commitment, organisational belonging and turnover intentions, as well as comparing the significance of their contribution towards these work attitudes. A sample of 285 participants drawn from the general population and University of Waikato undergraduate students completed an online questionnaire examining these concepts, and the hypotheses and research questions were empirically tested using correlation and multiple regression analyses. The results found that both PO Fit and state authenticity were significant contributors to job satisfaction, organisational commitment, organisational belonging and turnover intentions. Notably, one measure of PO Fit – the Person Organisation Fit Questionnaire emerged as the most significant contributor to all our chosen work attitudes. This study is among the first to compare PO Fit and authenticity on work attitudes, enriching the existing literature and offering vital insights for organisations. Indeed, it highlights the importance of prioritising PO Fit to enhance job satisfaction, nurturing organisational commitment and belonging, and reducing turnover intentions. Future research recommendations include investigating additional components within the broader Person-Environment fit framework, such as person-supervisor, person-job, and person-group fit, to better understand their influence on work attitudes. Additionally, intervention studies are recommended to evaluate strategies aimed at enhancing PO Fit and authenticity, and to assess their impact on positive work attitudes.