Terminalia chebula Retz. has been a valuable medicinal herb long ago that serves human health benefits. Nowadays, however, Terminalia chebula is used simply alone or in combination with other medicinal treatments, and there are few studies on the separation and assessment of biological activities, such as anti-inflammatory, antioxidant, and antibacterial properties from Terminalia chebula in Vietnam. This study aimed to examine the plant’s bioactivity and identify pure compounds. The results showed that in the anti-inflammatory assay through suppression of NO generation in RAW 264 cells, and the ethyl acetate fraction exhibited an IC50 value of 69.53 ± 3.69 μg/mL. Using DPPH for antioxidant assessment, the ethyl acetate fraction showed the highest activity, with IC50 values of 1.86 μg/mL. At 4 mg/mL, the ethanol extract, ethyl acetate, and methanol fractions showed resistance to Xanthomonas sp. For inhibition zone diameter measurements of 4.67 ± 0.57 mm, 2.67 ± 0.57 mm, and 4.33 ± 0.57 mm, respectively. At 10 mg/mL, these zone diameter measurements were 7.33 ± 0.58 mm, 6.33 ± 0.58 mm, and 8.33 ± 0.58 mm. Using column chromatography combined with the TLC technique, one compound was isolated and purified from bioactive ethyl acetate fraction. The structure was determined as 5-p-trans-coumaroylquinic acid based on NMR spectral data. The above results show that Terminalia chebula fruit is a potential material for developing plant-based antioxidant products.