Background The hawthorn has recently been used as a popular herbal medicine in food applications and phytotherapy, especially for the cardiovascular system. Methods In this study, phytochemicals were evaluated by LC-ESI-MS, GC-MS, and biological activity, including antioxidant (DPPH test) and antibacterial (broth dilution assay), in different extracts of Crataegus pentagyna fruit, leaf, and root. Results Globally, 49 phenolics were tentatively identified using HPLC-ESI-MS/MS in the hydro-methanolic extract of the fruit (major apigenin, caffeoylquinic acid derivative, and 4-O-(3′-O-glucopyranosyl)-caffeoyl quinic acid), 42 in the leaf (major salicylic acid, naringenin-6-C-glucoside, and naringin), and 33 in the root (major naringenin-7- O-neohesperidoside, isovitexin-2″-O-rhamnoside, and 4-O-(3′-O-glucopyranosyl)-caffeoyl quinic acid). The major group compounds analyzed by GC-MS in petroleum ether extracts were hydrocarbons (63.80%) and fatty acids and their derivatives (11.77%) in fruit, hydrocarbons (49.20%) and fatty acids and their derivatives (13.85%) in leaf, and hydrocarbons (53.96%) and terpenes (13.06%) in root. All samples exhibited promising phytochemical profile (total phenol, flavonoid, phenolic acid, and anthocyanin), antioxidant and antibacterial capacities, especially in hydro-methanolic extract of fruit (210.22 ± 0.44 mg GAE/g DE; 79.93 ± 0.54 mg QE/g DE; 194.64 ± 0.32 mg CAE/g DE; 85.37 ± 0.13 mg cyanidin 3-glucoside/100 g FW; DPPH: 15.43 ± 0.65 µg/mL; MIC: 0.15–0.62 µg/mL; and MBC: 0.62– 1.25 mg/mL), followed by the leaf and root extracts, respectively. The PCA and heatmap analysis results distinguished metabolite profile differences for samples. Conclusion The results of the present work provide scientific support for C. pentagyna as antimicrobial agents and natural antioxidants in human health and food preservation.