The unique advantages of nanozymes and their rapid advancement in biotechnology have opened a new emerging research field connecting nanotechnology and biotechnology. The number of nanozymes and their biological applications has exponentially increased, suggesting a promising future in practical applications. In this chapter, the features of various nanozymes, such as metal-based, metal oxides, metal-organic frameworks, single-atom-based, light-responsive, and chiral nanozymes are discussed. The properties of oxidase, peroxidase, superoxide dismutase, and catalase nanozymes are also summarized. Moreover, a comparison study was made between the kinetic behavior of natural enzymes and nanozymes. The recent applications of nanozymes in different biosensing techniques (fluorescence, colorimetric, electrochemical, and Raman), bioimaging, and therapeutics development have been reviewed. Based on the reported studies, the current challenges of using nanozymes and their prospects are summarized and discussed.