Algerian Phoenician juniper was a candidate for this work for isolating phytochemicals and manufacturing the green synthesis of zinc oxide nanoparticles to explore their biological potentialities. The polyphenolic contents were significantly higher in the aqueous decoction of Juniperus phoenicea L. leaves (AQE-JP). The synthesized nanoparticles were verified using various characterization techniques, including UV-VIS spectroscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray. The study confirmed that a granular hexagonal wurtzite structure was made. Its Crystallite size was 8.04 nm, and its absorption peak was 302 nm, with a band gap energy of 3.20 eV. The results showed that the aqueous decoction (AQE-JP) and ZnO NPs had excellent antibacterial, anti-inflammatory, and antioxidant properties. AQE-JP was better at antioxidant tests than ZnO NPs in several assays. These tests included DPPH (IC50 = 71.034 +/- 0.340 ug/ml), FRAP (EC50 = 23.67 +/- 4.86 ug/ml), and TAC (232.09 +/- 1.02 mg Eq AA/g DE). The ZnO-NPs, the other hand, showed vigorous antioxidant activity by stopping beta-carotene from turning color in the BCB assay (IC50 = 141.99 +/- 1.17 ug/ml). Both ZnO-NPs and AQE-JP were hemo-compatible and effectively prevented egg albumin denaturation. The ZnO NPs were more effective at the higher concentration tested (5 mg/ml), which created inhibition zones that were (16.4 +/- 0.32, 10.06 +/- 0.09, 13.2 +/- 0.14, and 12.2 +/- 0.18 mm for Bacillus subtilis, Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium respectively). These findings can be further utilized to analyze nano-directed drug delivery systems in silico/in vivo.