Introduction: Insulin resistance is a major contributor to mortality in adult populations worldwide, with alarming projections for the future. This condition can lead to hyperglycemia, hypertension, dyslipidemia, hyperuricemia, inflammation, endothelial dysfunction, a prothrombic state, type 2 diabetes mellitus, and cardiovascular disorders. Epicardial adipose tissue (EAT) has been linked to various conditions such as obesity, diabetes, hypertension, and coronary heart disease. This study investigated the correlation between EAT thickness and insulin resistance in non-diabetic young adults in Makassar. Methods: This observational cross-sectional study included 89 nondiabetic young adults who met the inclusion criteria. The study was conducted at Wahidin Sudirohusodo General Hospital and Hasanuddin University Teaching Hospital from September to November 2022. Epicardial fat thickness was measured using the GE Vivid E95 echocardiograph, and insulin resistance was assessed using the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR). Results: This study found a positive correlation between increased EAT thickness and insulin resistance. The mean EAT thickness in the insulin-resistant group was 2.36 ± 0.78 mm, while the mean EAT thickness in the non-insulin-resistant group was 1.72 ± 0.839 mm. Spearman correlation analysis confirmed a significant positive correlation between EAT thickness and HOMA-IR (R-value 0.320, p = 0.002). Conclusion: Our findings suggest that individuals with insulin resistance have thicker epicardial adipose tissue. The association between EAT and insulin resistance may be influenced by other factors such as obesity and dyslipidemia.