Objectives: Oxidative stress is implicated in several metabolic cascades involved in glucose control. Hence, investigating antioxidant and antidiabetic activities is crucial for discovering an effective diabetes mellitus (DM) agent. This study was aimed at probing the therapeutic efficacy of hydro-ethanolic extract of Combretum paniculatum (HECP) and gas chromatography-flame ionization detector (GC-FID)-identified phytochemicals as novel agents for DM. Methods: We determined the total phenols, flavonoids, and antioxidant vitamins in HECP using standard methods. A GC-FID was used to decipher phytochemicals of HECP. The antioxidant and antidiabetic activities of HECP were assessed using in vitro and in silico approaches. Results: The results revealed that HECP is affluent in phenols, flavonoids, and vitamin E and demonstrated engaging antioxidant activities in 1,1-diphenyl-2-picryl-hydroxyl (DPPH; IC50 = 0.83 µg/mL), thiobarbituric acid-reactive substances TBARS; IC50 = 2.28 µg/mL), and ferric-reducing antioxidant power assay (FRAP; IC50 = 2.89 µg/mL). Compared with the reference drug, acarbose, HECP exhibited good α-amylase and α-glucosidase inhibitory capacity, having IC50 values of 14.21 and 13.23 µg/mL, respectively, against 13.06 and 11.71 µg/mL recorded for acarbose. More so, the extract’s top 6 scoring phytochemicals (rutin, kaempferol, epicatechin, ephedrine, naringenin, and resveratrol) had strong interactions with amino acid residues within and around α-amylase and α-glucosidase active site domains. All the compounds but rutin had favourable drug-like characteristics, pharmacokinetics, and safety profiles when compared with acarbose. Conclusion: Altogether, our results vindicate the use of this herb in treating DM locally and reveal that it has pharmaceutically active components that could be used as novel leads in the development of DM drugs.