Objectives: This study was to standardize Trigonella foenum-graecum (fenugreek, TFG) seed extract by high-performance thin-layer chromatography (HPTLC) and to test its efficacy in ovariectomy-induced hyperlipidemia in rats. Materials and Methods: Hydroalcoholic extract of TFG-seed was standardized by HPTLC using diosgenin as standard. Female rats were selected and bilateral-ovariectomy was performed. Rats in Group-1 and Group-2 were healthy control and Ovariectomized (OVX) respectively. After 14-days of ovariectomy, Group 3 and Group 4 rats were administered TFG-extract (200 mg/kg/day) and 17β-estradiol (100 μg/kg/day), respectively, for 30 days. Serum lipid profile and liver oxidative markers were determined to compare between the groups. Results: The phytoestrogen, diosgenin, was found to be 0.83% w/w in the TFG-seed extract. The OVX rats exhibited a significant increase (P < 0.001) in serum cholesterol, triglycerides, low-density lipoprotein, and decreased high-density lipoprotein compared to control rats. The significant increase in thiobarbituric acid reactive substances and decreased glutathione was the indication of oxidative stress in the liver of OVX rats. Treatment with TFG extract significantly reverted these parameters in OVX rats which was comparable to that of standard 17β-estradiol. Conclusion: The favorable effect of TFG extract on ovariectomy-induced hyperlipidemia could be because of diosgenin along with other flavonoids and phenols in it. Thus, TFG has the benefits in menopause-induced hyperlipidemia and oxidative stress.