As an anti-diabetic medicinal plant, fenugreek seed (FG) (Trigonella foenum-graecum L.) has long been utilized and has many therapeutic uses. The current investigation sought to ascertain the effects of FG powder supplementation on insulin resistance, dyslipidemia, and oxidative stress in rats given a high-fat (HF) diet. Measurements of biochemical and antioxidant indicators were made in animal blood and tissue samples, including malondialdehyde (MDA), nitric oxide (NO), advanced oxidation protein product (AOPP), reduced glutathione (GSH), superoxide dismutase (SOD), triglycerides (TG), and catalase (CAT). Furthermore, the tissues of the kidney, heart, and liver were stained histologically. HF diet feeding in rats declined in antioxidant enzyme activities, along with a rise in MDA and other indicators of oxidative stress, which were mitigated by the supplementation of FG. Additionally, FG supplementation enhanced the expression of genes corresponding to antioxidants in the liver of rats given HF diet. FG supplements in HF diet-fed rats displayed altered gene expression in the livers that metabolized fat. Histological staining of the liver demonstrated that FG supplementation reduced necrosis and the accumulation of fat droplets in the liver of rats given HF diets. In conclusion, this finding showed that FG supplementation in HF diet fed rats reduced the plasma lipids, decreased oxidative stress and raised antioxidant enzyme activities. FG may therefore aid in reducing the chronic complications linked to the HF diet in experimental rats.