The current study adopted McAdams' multilayer framework as the basis to develop a psychological portrait of an elite athlete who was identified as being particularly 'mentally tough'. The aim was to use this single case as an exemplar to demonstrate the utility of McAdams' framework for understanding the complexity of sport performers across three domains of personality: dispositional traits, characteristic adaptations, and narrative identity. We operationalised these domains through the development of specific research questions and, subsequently, the collection and integration of the participant's Big Five traits, personal strivings, coping strategies, and response to a life story interview. The results offered a comprehensive insight into the nature of one athlete's personality that, in turn, informed conceptual perspectives of mental toughness in sport psychology literature and qualitatively supported emerging evidence of the validity of a three-layer framework in personality psychology. Specifically, the study's design showed how a holistic approach to personality analysis can lead to a more complete psychological representation of competitors in sport, and people generally. It demonstrated how motivational, sociocultural, and meaning-making aspects of personality can complement a trait profile to achieving a satisfying assessment of the whole person.