This review article focuses on the application of copper ions and nanoparticles as broad-spectrum antimicrobials, highlighting their potential as alternatives to rising antibiotic resistance. The mechanisms of bacterial, fungal, and viral inactivation by copper nanoparticles are discussed, along with the green biosynthesis methods using biomaterials. The antimicrobial efficacy of copper nanoparticles is demonstrated against various pathogens, including drug-resistant microorganisms such as MRSA and viruses like MERS and SARS-CoV-2. The article also explores the synthesis methods of copper nanoparticles, including physical, chemical, and biological approaches, with a focus on the advantages and disadvantages of each method. The green synthesis method, which uses biological materials like plant extracts, is highlighted for its cost-effectiveness, environmental friendliness, and ease of synthesis screening. The antimicrobial activity of copper nanoparticles is further enhanced when combined with other materials, such as polymers, carbon nanotubes, and chitosan, which can reduce toxicity and improve biocompatibility. The review concludes by discussing the future directions for green synthesized copper nanoparticles, including their potential in bioremediation and agricultural applications.This review article focuses on the application of copper ions and nanoparticles as broad-spectrum antimicrobials, highlighting their potential as alternatives to rising antibiotic resistance. The mechanisms of bacterial, fungal, and viral inactivation by copper nanoparticles are discussed, along with the green biosynthesis methods using biomaterials. The antimicrobial efficacy of copper nanoparticles is demonstrated against various pathogens, including drug-resistant microorganisms such as MRSA and viruses like MERS and SARS-CoV-2. The article also explores the synthesis methods of copper nanoparticles, including physical, chemical, and biological approaches, with a focus on the advantages and disadvantages of each method. The green synthesis method, which uses biological materials like plant extracts, is highlighted for its cost-effectiveness, environmental friendliness, and ease of synthesis screening. The antimicrobial activity of copper nanoparticles is further enhanced when combined with other materials, such as polymers, carbon nanotubes, and chitosan, which can reduce toxicity and improve biocompatibility. The review concludes by discussing the future directions for green synthesized copper nanoparticles, including their potential in bioremediation and agricultural applications.