The nanostructures synthesized using the green chemistry method have recently attracted the attention of scientists due to their significance in many scientific domains. This work provides an overview of the biosynthesis of zinc oxide (ZnO) nanosheets (NSs) using Phyllanthus emblica plant (PEP) extract. X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) were used to analyze the synthesized ZnO-NSs. Evaluation of the antibacterial activity of biosynthesized ZnO-NSs was performed. ZnO-NSs exhibit effective antibacterial activity against Gram-positive (S. pyogenes and S. aureus) and Gram-negative (S. typhi and E. coli) bacterial strains. S. typhi is the most sensitive microbe towards ZnO-NSs and formed a 21 mm zone of inhibition (ZOI). ZnO-NSs are also tested as a photocatalyst in the degradation of methyl orange (MO) and rhodamine B (RB). The degradation rate of MO was 90%, and RB was 96% after being exposed to UV light for 120 min. The as-synthesized ZnO-NSs exhibited selective dye degradation and showed relatively better photocatalytic activity for positively charged (cationic) dyes. This work could lead to the fabrication of high-yield photocatalysts, which have the potential to degrade textile dyes from aqueous solution.