In order to address the drastic demand for novel broad-spectrum antibacterial and anticancer medicines with enhanced activity, computer modelling was utilized to rationally develop newer anticancer triazole based drugs. A unique series of benzo[d][1,3]oxazin-4-one linked 1,2,3-triazoles was synthesised in five steps, with good yields and an assessment of their antibacterial and anticancer activities. IR spectroscopy, 1H NMR, 13C NMR, and mass spectrometry were used to characterize the synthesis of triazole compounds. From antibacterial screening, the prepared derivatives namely, 8a, 8e, 8h and 8k showed excellent inhibitory potential against S. aureus with ZI of 28 ± 0.48, 30 ± 0.42, 30 ± 0.11, 35 ± 0.23 mm respectively, compared to moxifloxacin (33 ± 0.15 mm). Compared to doxorubicin (IC50 = 2.45 ± 0.14 μM), compounds 8h and 8k demonstrated superior and exceptional cytotoxicity against the A549 cell line (IC50 = 2.30 ± 0.26 and 1.90 ± 0.30 μM, respectively). Latter All the derivatives were further subjected to in silico docking studies against human lung (PDB: 2P85), VEGFR2 kinase domain (PDB: 3CP9) and could serve as ideal leads for additional modification in the field of anticancer research. Based on docking results, 8e showed that the amino acids Arg373(A), Gly113(A), Glu103(A), Asp108(A), Ser119(A), Asn375(A), Val374(A), Lys387(A), and Asn120(A) exhibited highly stable binding to cytochrome P4502A13 receptor of lung cancer. Furthermore, Density Functional Theory (DFT) calculations are performed to support the molecular docking studies. Compounds 8e, 8h, and 8k were discovered to have estimated energy gaps (eV) of 3.181, 4.034, and 3.539 eV, respectively. Triazole 8h exhibited the lowest chemical hardness (1.962 eV) and the highest chemical softness (0.252 eV), which also suggests that it is more reactive than all the other compounds under study. Moreover, these scaffolds physicochemical characteristics, filtration molecular properties, assessment of toxicity, and bioactivity scores were assessed in relation to ADME (absorption, distribution, metabolism, and excretion). In conclusion, we discovered a novel benzoxazinone linked 1,2,3-triazoles with promising antimicrobial and anticancer activity and a favorable pharmacokinetic profile.