Authenticity at work refers to the extent to which a worker feels in touch with their true self while at work. At first sight this concept seems to overlap with the concept of person-environment (P-E) fit, that is, the degree to which an individual experiences good fit with their work environment. Drawing on a sample of 867 Dutch gifted workers, structural equation modeling was used to investigate (i) whether authenticity at work and P-E fit can be distinguished, and (ii) how authenticity at work and P-E fit were associated with employee well-being. As expected, confirmatory factor analysis revealed that authenticity at work and P-E fit were distinct from each other. Moreover, the mediated effect of authenticity at work was stronger for two negative forms of well-being (burnout and boredom) than for two positive forms of well-being (work engagement and job satisfaction). The theoretical and practical implications of these findings are discussed, especially focusing on the distinction between authenticity and P-E fit.