The unique features of zinc oxide (ZnO) materials, including their large surface area, chemical stability, biocompatibility, and high electron mobility, have prompted much research into their possible use in sensors. ZnO nanomaterials hold significant promise for advancing sensor technology across various fields, including environmental monitoring, health care, and industrial applications. Ongoing research focuses on overcoming current challenges to fully exploit their potential. A variety of sensors based on different ZnO nanomaterials are categorically complied in this chapter. Various fabrication methods including low temperature (sol–gel, hydrothermal, solvochemical) and high temperature (CVD, electrospinning, pyrolysis) methods are discussed for ZnO nanomaterials. ZnO nanomaterials-based electrodes have been used in fabricating a variety of sensors such as gas sensors, UV sensors, biosensors, humidity sensor, and electrochemical sensors which are described in detail including their fabrication, selectivity, sensing parameters, reliability, and stability of sensors. This, sensor technology in a variety of domains, such as industrial applications, health care, and environmental monitoring, might be greatly advanced by ZnO nanoparticles.