Seaweeds are known for their beneficial health effects in the management of diabetes mellitus (DM). Numerous bioactive metabolites of diverse chemical structures have been found in the marine algae with attributed potent pharmacological effects. The current study was carried out to gain insights into the precise interaction and the inhibitory mechanism of bioactive components, obtained from seaweed, against protein tyrosine phosphatase 1B (PTP1B), the enzyme with a crucial role in insulin insensitivity, and α-glucosidase, which performs the key function in postprandial carbohydrate hydrolysis. Inhibitors of these proteins might be suitable for the management of DM type 2. Molecular docking experiments have shown that the antidiabetic compounds preferably bind to the allosteric site of PTP1B, sandwiched between α3, α6 and α7 helices, with a lesser ΔG value in comparison to the active site. Interacting orientation of eckol, dieckol, 7-phloroeckol, and phlorofucofuroeckol-A was comparable to that of the reference compound. In contrast, the compounds interacted with a-glucosidase at the active site with appreciable affinity. Phlorofucofuroeckol-A, dieckol, and eckol demonstrated high inhibitory potential against the protein as compared to acarbose possibly due to the relatively large molecular size and the presence of numerous OH groups, and additional hydrophobic and π-π interactions that are missing in the acarbose-α-glucosidase complex. The estimated affinity of the compounds showed good correlations with experimental results for both enzymes. The described interaction patterns are essential for understanding the mechanisms responsible for the antidiabetic effects of marine algae.