Obesity-induced inflammation contributes to the development of metabolic disorders such as insulin resistance, type 2 diabetes, fatty liver disease, and cardiovascular disease. In this study, we investigated whether the combination of eicosapentaenoic acid (EPA) and capsaicin could protect against high-fat diet (HFD)-induced obesity and related metabolic disorders. The experiments were performed using male C57BL/6J mice that were fed one of the following diets for 10 weeks: standard chow (5.3% fat content) (normal group), a HFD (32.0% fat content) (HFD group), or a HFD supplemented with either 4% (w/w) EPA (EPA group) or a combination of 4% (w/w) EPA and 0.01% (w/w) capsaicin (EPA+Cap group). Our results indicated that the body, fat and liver tissue weights and levels of serum glucose, insulin, total cholesterol, triglyceride, high-density lipoprotein-cholesterol, aspartate aminotransferase, and alanine aminotransferase were significantly higher in HFD group mice than in normal group mice ( p <0.05 in all cases). However, the body and fat tissue weights and serum glucose levels and homeostasis model assessment of insulin resistance were significantly lower in EPA+Cap group mice group than in HFD and EPA group mice ( p <0.05 in all cases). Thus, our study suggests that the combination of EPA and capsaicin might be beneficial for delaying the progression of obesity-related metabolic dysregulation and subsequent complications.