Background. Type 2 diabetes mellitus is one of the most common metabolic diseases, characterized by chronic hyperglycemia and numerous associated complications. One approach to controlling postprandial hyperglycemia is the inhibition of α-glucosidase. Given the potential side effects of synthetic α-glucosidase inhibitors, particularly acarbose, there is a pressing need to identify natural sources of bioactive compounds with similar activity. Salvia officinalis is rich in bioactive compounds and is a promising natural source for treating metabolic disorders associated with diabetes mellitus. Aim. To evaluate the inhibitory effects of hydroethanolic extracts obtained from the leaves of S. officinalis on α-glucosidase activity in vitro. Methods. The effects of 50% and 70% hydroethanolic extracts of S. officinalis on α-glucosidase activity were evaluated as described in [1]. To compare the inhibitory potency of the crude extracts, α-glucosidase inhibition was assessed at three extract concentrations corresponding to total polyphenol contents of 50, 100, and 200 μg GAE/mL. Acarbose was used as a reference inhibitor. For kinetic analysis, α-glucosidase activity was measured at varying concentrations of pNPG (0—3 mM) in the absence or presence of acarbose or S. officinalis extracts at their respective IC50 values. The mode of inhibition was evaluated using Lineweaver-Burk plots [2]. Results. A high potential of biologically active compounds present in 50% and 70% extracts of S. officinalis to inhibit α-glucosidase activity in vitro has been confirmed. Both extracts effectively inhibited the enzyme, with the 70% extract demonstrating stronger inhibitory activity (IC₅₀ of 56.8 μg/mL) than the 50% extract (IC₅₀ of 168.0 μg/mL). The higher inhibitory activity of the 70% extract may be attributed to its higher polyphenol content (287.7 ± 2.3 μg GAE/mL), which was 1.7-fold higher than that of the 50% extract (168 ± 1.9 μg GAE/mL). The inhibitory effects of both extracts were markedly stronger than those of the positive control, acarbose (IC₅₀ of 6.0 mg/mL). It was found that, the 70% extract of S. officinalis exhibited a mixed mode of α-glucosidase inhibition. Conclusions. The results indicate the potential of S. officinalis leaves as a source of bioactive compounds for the development of herbal medicinal products and functional foods to prevent and correct metabolic disorders associated with hyperglycemia.