Background Psychiatric factors such as depression, anxiety, and life stressors have been shown to negatively affect diabetes self-management and A1C in children and adolescents. However, less is known about how trauma exposure and symptoms of post-traumatic stress disorder (PTSD) may affect type 1 diabetes. Objectives To determine the rates of trauma exposure and PTSD symptoms in patients aged 7–21 years with type 1 diabetes and to examine the relationships among trauma exposure, PTSD, anxiety, depression, and diabetes self-management. Methods Patients underwent standardized psychiatric screening questionnaires during clinic visits. A1C at goal was defined as <7.0%, and behavioral adherence was defined as specific parameters of blood glucose monitoring. χ2 and Fisher exact tests were used to assess the relationships among trauma, PTSD, anxiety, and behavioral adherence. ANOVA was conducted to examine group differences between A1C and the presence of suicidal ideation. Results Of the participants, 38.4% (n = 99, mean age 13.8 ± 3.5 years, 51.5% female) had trauma symptoms and functional impairment concerning for PTSD. Rates of trauma secondary to accidental injury, medical traumatic stress, natural disaster, and witness to family violence were 28.3, 22.2, 10.1, and 6.1%, respectively. Neither PTSD, anxiety, nor depression symptoms were associated with behavioral nonadherence (P = 0.546, P = 0.337 and P = 0.697, respectively), but the subscales for significant school avoidance and generalized anxiety disorders were associated with behavioral nonadherence (P = 0.023 and P = 0.032, respectively). Those who reported suicidal ideation had higher mean A1C than those who did not (A1C 8.9 vs. 8.3, P = 0.047). Conclusion Although trauma was common among youth with type 1 diabetes, neither trauma nor PTSD was associated with changes to self-management. However, certain forms of anxiety and suicidal ideation were associated with poor self-management and higher A1C, respectively.