The current research work attempted to investigate the strontium oxide nanoparticles (SrONPs) synthesized from the Lantana camara leaf extract. The bio-synthesized strontium nanoparticles were characterized by a UV-Visible spectrometer, Fourier Transform Infra-Red spectra (FTIR), Scanning Electron Microscope, X-Ray diffraction, and Dynamic Light Scattering. The biomolecules in the extraction of plant leaves behaved as good reducing and capping agents. The XRD peaks are indexed to 13.020, 22.240, 25.940, 31.310, 34.000, and 40.910, and the corresponding planes are (101), (112), (202), (213), (310), and (312) representing cubic structure for SrNPs. The strontium nanoparticles are unevenly globular in shape, and chaos, and exhibited cluster and partially even surfaces shown from the Scanning Electron Microscope. The antibacterial assay of the synthesized Lantana camara strontium oxide nanoparticles was evaluated. The binding effect was more at higher concentrations (100 µl) than the control for the species E. coli (21 mm), and A. niger (20 mm).