The present study is to evaluate the inhibitory activity of α-amylase and α-glucosidase enzymes in the methanol extracts of marine red alga Tolypiocladia glomerulata. The methanol extract of red alga T. glomerulata showed concentration dependent α-glucosidase inhibitory and with achieved maximum activity of 87.08 ± 0.01% at a concentration of 900 µg/mL in a manner IC50 = 608 µg/mL. Similarly the dose dependent effect was observed against α- amylase enzyme with 81.25 ± 0.02% of inhibition at 900 µg/mL (IC50 = 543 µg/mL). The above results were compared with that of the standard drug Acarbose. It can be concluded that the methanol extracts of red alga T. glomerulata exert an effective antidiabetic activity and considered as a potential candidate for the management of diabetes mellitus.