Background: Type 1 diabetes mellitus (T1DM) is a chronic condition characterized by hyperglycemia and typically managed with insulin. Improved glycemic control often results in weight gain, increasing the risk of comorbid disordered eating behaviors (DEBs) and eating disorders (EDs). Eating disorders (ED) are one of the most prevalent mental issues that today's teenagers confront, characterized by a distorted attitude toward weight and form, as well as a distorted sense of body shape. Patients with T1DM are also more prone to anxiety and depression, which may negatively impact metabolic control. Methodology: A cross-sectional descriptive study was conducted at the Diabetes Treatment Center (DTC) of Prince Sultan Military Medical City, Riyadh. A total of 150 adults with T1DM (aged 14–40 years) participated. Data were collected using a self-administered questionnaire, including demographic and clinical variables, the Diabetes Eating Problem Survey-Revised (DEPS-R) for DEBs, and the Hospital Anxiety and Depression Scale (HADS). Descriptive statistics and chi-square tests were performed using SPSS v23. Results: DEBs were reported in 32.0% of females and 25.3% of males, with no statistically significant gender difference. Depression prevalence was 4.0% in females and 1.3% in males. Anxiety was significantly higher in females (16.0%) compared to males (5.3%, p = 0.009). No significant associations were found between DEBs, anxiety, or depression and age, HbA1c, insulin type, BMI, smoking status, or duration of diabetes. Conclusion: Psychological comorbidities are common among adults with T1DM, particularly in females. Anxiety and DEB symptoms affect quality of life and should be prioritized in diabetes care. Routine screening and tailored interventions are recommended.