Importance: Exercise intolerance is associated with increased risk for morbidity and mortality in childhood cancer survivors. However, an association between exercise intolerance and psychosocial outcomes has not been fully explored. Objective: To examine the associations between exercise intolerance and emotional distress, attainment of social roles, and health-related quality of life in childhood cancer survivors. Design, Setting, and Participants: A cross-sectional study including 1041 adult survivors of childhood cancer and 286 community controls in the St Jude Lifetime Cohort was conducted at St Jude Children's Research Hospital. The study was performed from April 1, 2012, to March 15, 2020. Exposures: Exercise intolerance was defined as relative peak oxygen uptake less than 85% of age- and sex-estimated levels from maximal cardiopulmonary exercise testing. Main Outcomes and Measures: Emotional distress was measured with the 18-item Brief Symptom Inventory-18, which includes overall Global Severity Index and depression, anxiety, and somatization subscales. Participants with T scores greater than or equal to 63 were classified as having elevated levels of distress. Social attainment was evaluated using patient-reported educational, employment, and marital status. Health-related quality of life was examined with the Medical Outcomes Survey Short Form-36. Participants with T scores less than or equal to 40 were classified as reporting poor health-related quality of life. Results: Of the 1041 participants, 528 were women (50.7%). The prevalence of exercise intolerance among survivors (mean [SD] age, 35.5 [9.2] years) was higher than that among controls (age, 34.5 [10.0] years) (survivors: 634 [60.9%] vs controls: 75 [26.2%], P <.001). After adjusting for age at diagnosis and cardiopulmonary exercise testing, sex, race/ethnicity, smoking, physical activity, and exercise intolerance were associated with an increased risk for anxiety (prevalence rate ratio [PRR], 1.95; 95% CI, 1.20-3.16), somatization (PRR, 1.86; 95% CI, 1.23-2.80), and unemployment (PRR, 1.76; 95% CI, 1.23-2.52); an inverse association was noted with having a college degree (PRR, 0.67; 95% CI, 0.50-0.88). Exercise intolerance was associated with an increased the risk for scoring less than or equal to 40 on the physical component summary of the Medical Outcomes Survey Short Form-36 (PRR, 3.69; 95% CI, 2.34-5.84). These associations persisted when either cancer treatment exposures or chronic health conditions were added to the model. Conclusions and Relevance: The findings of this study suggest that exercise intolerance is independently associated with emotional distress, attainment of social roles, and health-related quality of life of long-term survivors of childhood cancer. The results also suggest that improving physiologic capacity may benefit general health and wellness, as well as emotional health, ability to participate in social roles, and health-related quality of life.