Background: Thyroid dysfunction is a common endocrine disorder, often coexisting with diabetes mellitus due to shared pathophysiological mechanisms. Understanding the relationship between thyroid hormone levels and diabetes is crucial for improving clinical outcomes in affected patients. This study aims to compare thyroid hormone levels in diabetic and non-diabetic individuals to identify potential variations. Materials and Methods: A cross-sectional study was conducted involving 200 participants, including 100 diabetic patients and 100 age- and sex-matched non-diabetic controls. Blood samples were analyzed for fasting blood glucose, glycosylated hemoglobin (HbA1c), and thyroid hormones, including triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH), using standard chemiluminescent immunoassay techniques. Statistical analysis was performed using SPSS, with the independent t-test applied to compare group differences, and a p-value < 0.05 was considered significant. Results: The mean TSH level in diabetic patients was significantly higher (4.2 ± 1.5 µIU/mL) compared to non-diabetic controls (2.8 ± 1.2 µIU/mL; p < 0.001). Similarly, a lower mean T3 level was observed in diabetics (0.9 ± 0.3 ng/mL) compared to non-diabetics (1.2 ± 0.4 ng/mL; p = 0.002). However, no significant difference was noted in T4 levels between the groups (p = 0.09). Subclinical hypothyroidism was more prevalent in diabetic patients (30%) compared to non-diabetic controls (10%). Conclusion: The study highlights a higher prevalence of thyroid dysfunction, particularly subclinical hypothyroidism, in diabetic patients compared to non-diabetic controls. These findings underscore the importance of routine thyroid screening in individuals with diabetes to ensure timely detection and management of thyroid abnormalities, potentially improving overall metabolic control.