A lot of materials are emerging as the advanced materials with significantly improved properties and out of these materials. Carbon nanotube (CNT)-based nanocomposites have revolutionized the field of materials science. These CNT-based nanocomposites have revolutionizing multiple industries through their exceptional mechanical, electrical, and thermal properties. The incorporation of CNTs into various matrix materials, such as polymers, metals, and ceramics, has significantly enhanced the performance of nanocomposites, leading to advancements in specific advanced industries such as aerospace, automotive, biomedical, electronics, and high strength structural applications. The associated properties with such materials have high aspect ratio, low density, and superior conductivity, which make them ideal for next-generation materials with enhanced durability, light-weight structures, and scope of multifunctionality. This chapter explores the diverse applications of CNT-based nanocomposite materials with different compositions, emphasizing their advanced role in various engineering applications. The chapter also discusses various material systems, including polymer-CNT, metal-CNT, ceramic-CNT, and hybrid CNT composites, along with their tailored properties and specific applications. Further, an in-depth analysis of the different processing techniques, such as solution mixing, melt blending, in situ polymerization, electrospinning, and spark plasma sintering, highlighting their influence on composite properties is highlighted in the chapter. Some new processing routes such as microwave heating, laser processing, and hybrid processes are explored in this chapter. With ongoing improvements in dispersion techniques and scalable manufacturing, these nanocomposites hold immense promise for the future of advanced materials. This chapter serves as a comprehensive guide to understanding the transformative impact of CNT-based nanocomposites and their potential in shaping next-generation technological advancements.