Nanotechnology and nanomaterials present a transformative approach to air purification, offering innovative solutions that can significantly enhance the efficiency and effectiveness of pollutant removal. The unique properties of nanomaterials, such as increased surface area, enhanced reactivity, and improved catalytic performance enable the development of advanced filtration, adsorption, and catalytic systems that address various air quality challenges with better performance compared to conventional air purification technologies. This chapter provides a brief introduction to nanotechnology applications for improving air quality, such as nano-filtration, nano-adsorption, and nano-photocatalysis. The challenges of the application of these technologies for air pollutant removal in the real world and future perspectives are also discussed.