The rise of nanotechnology has brought to the world a new potential and broader perspective of what humanity can achieve through material manipulation at the nanoscale. In the past two decades, ZnO NPs have become one of the most popular metal oxide nanoparticles in biological applications due to their excellent biocompatibility, economic, and low toxicity. Interestingly, the green method of synthesis using plant sources have been found appropriate for the production of ZnO NPs dues to its numerous health, environmental, economic, and medicinal benefits. Due to the large rate of toxic chemicals and extreme environment employed in the physical and chemical production of these nanoparticles, green methods employing the use of plants, fungus, bacteria, and algae have been adopted. Zinc oxide nanoparticles have been successfully obtained by green synthesis using different biological substrates. ZnO NPs have emerged a promising potential in biomedicine, especially in the fields of anticancer and antibacterial fields, which are involved with their potent ability to trigger excess reactive oxygen species (ROS) production, release zinc ions, and induce cell apoptosis. This review summarizes the green synthesis and recent advances of ZnO NPs in the biomedical fields, which will be helpful for facilitating their future research progress and focusing on biomedical fields.