Phytoestrogens, a diverse group of naturally occurring plant-derived chemicals that resemble estradiol, have garnered considerable interest for their potential effects on insulin sensitivity and glucose metabolism. These chemicals primarily exert their effects via estrogen receptors and numerous signaling pathways, including PI3K/Akt, AMPK, and PPARγ, therefore influencing glucose absorption, lipid metabolism, and inflammatory responses. Experimental and clinical investigations have demonstrated favorable benefits of phytoestrogens, notably isoflavones such as genistein and daidzein, in diminishing insulin resistance, enhancing β-cell functionality, and alleviating characteristics of metabolic syndrome. Nonetheless, interindividual heterogeneity, particularly concerning gut microbiota and equol-producing capability, influences efficacy findings. Although phytoestrogens provide a botanical and practical method for addressing insulin resistance and associated metabolic conditions, such as type 2 diabetes and PCOS, comprehensive safety data and extensive clinical validation are still insufficient. This review rigorously examines the mechanisms of action, preclinical and clinical data, and prospective therapeutic potential of phytoestrogens in enhancing insulin sensitivity.