Objective: This study was carried out to investigate the potential of Dunaliella salina microalgae to ameliorate obesity induced by high-fat diet (HFD) in male Wistar rats.Methods: Fifty rats weighing 150–160 g were fed HFD for 12 weeks. The rats were randomly divided into five groups of ten rats each. Obese rats were orally administered D. salina ethanolic extract (150 mg/Kg body weight), and orlistat as standard drug (12 mg/Kg body weight), for 6 weeks.Results: Treatment of obese rats with both D. salina and orlistat had a significant effect in reducing body and liver weights as well as visceral fat, inhibiting pancreatic lipase activity, decreased lipid profile, and increased fecal fat and ameliorating liver function enzymes activity, insulin, blood glucose, and leptin levels. Besides, food intake was insignificantly increased as a result of D. salina and orlistat treatments compared with normal control rats.Conclusion: It could be concluded that D. salina rich in β-carotene significantly reduced body weight gain and ameliorated several metabolic pathways implicated in obesity and its related complication. Hence, further intensive study must be carried out to formulate D. Salina extracts to apply as a promising natural anti-obesity nutraceutical drug.