There are little to no data on whether any associations exist between sport specialization and mental health in youth softball athletes. Highly specialized youth softball athletes will have worse self-reported depression and anxiety symptom scores compared with low and moderate specialized athletes. Cross-sectional survey. Level 4. An online cross-sectional survey was distributed in the fall of 2021 to a national sample of female youth softball athletes between the ages of 12 and 18 years. Sport specialization status was determined using a 3-point specialization scale that classifies either low, moderate, or high. The patient health questionnaire-9 (PHQ-9) and the 7-item general anxiety disorder scale (GAD-7) were used to assess self-reported symptoms of depression and anxiety. Comparison also included sports participation and specialization behaviors between specialization groups. A total of 1283 subjects (mean age, 15.1 ± 1.7 years) fully completed the survey. After adjusting for covariates, lower scores were reported on both the PHQ-9 and GAD-7 by highly specialized athletes compared with moderate or low specialization athletes (PHQ-9, high = 8.6 ± 0.4; moderate = 11.2 ± 0.3; low = 10.9 ± 0.5; P < 0.01; GAD-7, high = 6.5 ± 0.4; moderate = 8.6 ± 0.3; low = 8.4 ± 0.4, P < 0.01). Conversely, higher scores were reported on both scales for athletes who received private softball coaching compared with those who did not (PHQ-9, 11.5 ± 0.3 vs 9.0 ± 0.3; P < 0.01; GAD-7, 8.8 ± 0.3 vs 6.9 ± 0.3, P < 0.01). Finally, athletes who reported an arm overuse injury in the previous year reported higher PHQ-9 scores (10.8 ± 0.3 vs 9.8 ± 0.3; P < 0.01). While sport specialization, as measured by the validated 3-point scale, was not associated with increased anxiety and depression symptom scores, other aspects of specialization behavior such as private coaching or overuse injury history were associated with worse scores on these scales, indicating potential concern for anxiety and depression. However, although the differences we observed were statistically significant, they did not exceed the minimal clinically important difference values that have been established for the PHQ-9 (5 points) or GAD-7 (4 points). This project is a first step toward understanding the sport specialization behaviors and their influence on the mental health of youth softball athletes. Focusing on investigating specialization behaviors further may reveal to be a better indicator of risk of developing anxiety and depression symptoms compared with utilizing the 3-point specialization scale.