This study evaluated the nutraceutical potentials of Ocimum gratissimum and Ocimum basilicum leaves, focusing on proximate, phytochemical, antioxidant, enzyme inhibitory, and anti-inflammatory activities. Fresh leaves collected from Akure, Nigeria, were authenticated, shade-dried, powdered, and extracted with 70% ethanol. Standard methods were applied for proximate and phytochemical composition, while antioxidant capacity was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, ferric reducing antioxidant power (FRAP), and lipid peroxidation inhibition (LPI) assays. Enzyme inhibitory assays targeted α-amylase, α-glucosidase, lipase, and protease, while anti-inflammatory potential was determined via protein denaturation inhibition. All analyses were performed in triplicate. Significant compositional and functional differences were observed between the two species. O. gratissimum recorded higher moisture, crude fat, nitrogen-free extract, saponins (78.99 ± 1.33 mg/g), phenolics (18.12 ± 0.30 mg GAE/g), DPPH activity (60.65 ± 0.67%), α-glucosidase inhibition (43.37 ± 0.95%), protease inhibition (91.75 ± 0.14%), and albumin denaturation inhibition (10.48 ± 0.66%). In contrast, O. basilicum exhibited higher crude ash, fibre, tannins (10.04 ± 0.17 mg/g), alkaloids (4.23 ± 0.08%), flavonoids (1.01 ± 0.17 mg QE/g), vitamin C (1.04 ± 0.02 mg/g), LPI (53.88 ± 0.78%), α-amylase inhibition (20.10 ± 1.34%), and lipase inhibition (66.55 ± 0.61%). No significant differences were noted in crude protein, ABTS scavenging, or FRAP values. Overall, O. gratissimum appears more effective against oxidative stress and inflammation, while O. basilicum shows stronger potential for glycemic and lipid regulation. These findings highlight their complementary nutraceutical roles and suggest both species as promising candidates for functional food and nutraceutical development.