The use of nanotechnology has resulted in significant advancements across a wide range of industries in recent years. Nanomaterials are the cornerstone upon which nanotechnology is built. It is clear that nanoparticles possess unique properties when contrasted with bulk materials. Noble metal nanoparticles (NMNs) have become a famous nanomaterial due to the compelling visual and chemical properties that they possess due to their composition. Today, NMNs have a wide variety of applications, including but not limited to the following: catalysis, biosensors, bioimaging, theragnostic, antimicrobial, cosmetics, medical devices, and a seemingly endless number of other applications. Following is some of the topics that have been discussed in this chapter of the book: the current state of nanotechnology; techniques for characterising nanoparticles; optical properties; various applications of nanoparticles in medical biotechnology; “and synthetic strategies for nanoparticles, including top-down, bottom-up, and biological approaches.