Background <p>Sport-related concussion has been associated with adverse psychological outcomes such as anxiety and depression. However, little is known about how concussion history relates to broader psychosocial functioning, including well-being and personality traits that influence long-term psychosocial adaptation. Clarifying these associations may provide insight into individual variability in recovery and the potential long-term psychosocial consequences of concussion. Therefore, the purpose of this study was to compare well-being and personality traits among collision-sport athletes with concussion history, those without concussion history, and non-athletes. As an exploratory objective, we examined whether the number of previous concussions was associated with well-being and personality traits among athletes with concussion history.</p> Methods <p>Twenty-two male collision-sport athletes with concussion history, 33 male collision-sport athletes without concussion history, and 38 healthy male non-athlete controls participated. Participants completed self-reported questionnaires using an online survey form. Well-being was assessed using measures of psychological well-being, affective well-being, and life satisfaction. Personality traits were evaluated using the Ten-Item Personality Inventory, the Interpersonal Reactivity Index, and the Rosenberg Self-Esteem Scale. Group differences were examined using analysis of covariance adjusted for age and General Health Questionnaire-12 score. Exploratory associations between the number of previous concussions and well-being or personality traits were examined among athletes with concussion history.</p> Results <p>Collegiate student-athletes with a history of concussion had significantly lower Personal Growth, a subscale of psychological well-being, and Empathic Concern, a subscale of the Interpersonal Reactivity Index, compared with athletes without concussion history (both adjusted <i>p</i> = .006). Compared with non-athletes, athletes with concussion history had significantly lower scores for Personal Growth, Agreeableness, and Empathic Concern (adjusted <i>p</i> = .011, .002, and .006, respectively), with Agreeableness representing a subscale of the Ten-Item Personality Inventory. In the exploratory analysis, no significant associations remained between the number of previous concussions and well-being or personality traits after Benjamini-Hochberg false discovery rate correction.</p> Conclusion <p>These findings indicate that collision-sport athletes with concussion history may be associated with lower levels of well-being and difficulties in interpersonal relationships. Further research is needed using a prospective cohort design to track well-being and personality changes following concussion to understand the psychosocial consequence of sport-related concussion.</p>