Diabetes mellitus (DM) is a chronic metabolic disorder characterized by persistent hyperglycemia. The prevalence of Diabetes mellitus is expected to increase to 5.3% by 2030. This study aimed to determine the effects of ethanolic extract of Cyperus esculentus tubers on alloxan-induced diabetes mellitus and lipid profile in male Wistar rats. A total of 25 Wistar rats were used for the study. Diabetes was induced by injection of alloxan 100 mg/kg and rats with blood glucose levels 200 mg/kg and above were considered diabetic. The rats were randomly divided into five groups (n = 5), group 1, normal control, group II, negative (diabetic) control, and Group III and Group IV were diabetic rats treated with 400mg/Kg and 800mg/Kg body weight of the ethanolic extract of Cyperus esculentus tubers and group V were diabetic rats treated with 10mg/Kg body weight Metformin. All treatments lasted for 28 days and Blood glucose levels were checked at weeks 0, 1, 2, 3, and 4 respectively. At the end of the treatment period, the rats were sacrificed and the blood samples collected were used to determine serum insulin level and lipid profile. The result obtained revealed a statistically significant (P<0.05) decrease in blood glucose levels in groups III, IV, IV, and V as compared to the diabetic untreated group. The results of serum total cholesterol revealed a significant decrease in group I and group IV. However, high-density lipoprotein shows a significant decrease in group V as compared to the diabetic untreated group. There was also a statistically significant decrease (P<0.05) in low-density lipoprotein (LDL) levels in groups I, III, and IV when compared with the diabetic untreated group. There was also a statistically significant (p < 0.05) increase in serum insulin level in the normal control group and the group treated with 800mg/kg of extract. This study revealed the potential benefits of the ethanolic extract of Cyperus esculentus tubers in reducing blood glucose levels and its effects in reversing hyperlipidemia associated with diabetes mellitus.