In this study, the antiviral potential of ethanol (80%) extracts of Hyoscyamus niger L. leaves and seeds was theoretically investigated against SARS-CoV-2 proteins (PDB IDs: 7MRV, 7QO7, and 7U0N) using molecular docking and ADME/T analysis. The chemical composition of the extracts was determined by GC-MS, revealing significant variations in phytochemical profiles between plant organs. Docking simulations were performed on 31 major compounds identified from the extracts. Among them, 6-Amino-2,4-dimethyl-5-methoxyquinoline, Isosteviol methyl ester, and 6-Hydroxy-1,4-dimethylisoquinoline exhibited the most favorable binding affinities and interaction profiles across all target proteins. The ADME/T properties of 6-Amino-2,4-dimethyl-5-methoxyquinoline were further analyzed, demonstrating ideal pharmacokinetic characteristics such as high membrane permeability, good solubility, and excellent oral absorption potential. The results suggest that specific bioactive components in H. niger may serve as promising lead compounds for antiviral drug development against SARS-CoV-2 and warrant further in vitro and in vivo validation.