Olive leaf extract (OLE) is a natural product derived from the leaves of the olive tree (Olea europaea). This study was carried out in order to understand the effect of its aqueous leaf extract on cholesterol, triglycerides, high-density lipoproteins (HDL), and low-density lipoprotein (LDL) levels in male Wistar rats fed with high-fat diet. Fifteen male Wistar rats were divided into three groups: control (normal diet), high-fat diet (HFD) only, and HFD + Aqueous Olea europaea (olive) leaf extract groups. The rats in the HFD + Aqueous Olea europaea (olive) leaf extract group received a daily oral administration of Aqueous Olea europaea (olive) leaf extract at a dose of 200 mg/kg body weight for three weeks after being fed a high-fat diet for five weeks. The results showed that the high-fat diet group exhibited elevated levels of total cholesterol (TCHOL) and Low-density lipoprotein (LDL) level compared to the control group (normal diet). However, there was a statistically significant reduction (p < 0.05) in total cholesterol and LDL levels in group receiving Aqueous Olea europaea (olive) leaf extract alongside the high-fat diet when compared to those receiving high-fat diet alone (HFD group). Triglyceride (TG) and High-density Lipoprotein (HDL) levels did not show significant differences among the groups. This study highlights the adverse effects of a high-fat diet on cholesterol levels in male Wistar rats and demonstrates the beneficial impact of Aqueous Olea europaea (olive) leaf extract in mitigating these effects. Keywords: Olea europaea, hypercholesterolemia, high fat diet, lipid profile, Wistar rats.