The use of ultrasonics in materials synthesis offers a versatile and powerful approach to synthesis nanomaterials with unique properties. Sonochemical synthesis is a method that employs high-frequency ultrasound waves to drive chemical reactions, resulting in the creation of nanomaterials. This approach binds the physical and chemical impacts of ultrasound-induced cavitation, which involves the formation, expansion, and explosive collapse of bubbles in a liquid medium. The asymptomatic conditions generated by ultrasonic cavitation in appropriate chemical precursors open new pathways for material development, with significant implications across various fields, from catalysis and energy to medicine and environmental science. The sonochemistry controls the physical effects of ultrasonic cavitation—specifically, the formation, growth, and implosive collapse of bubbles in a liquid medium—to create localized extreme conditions that facilitate unique chemical reactions. These conditions, characterized by high temperatures and pressures, promote the efficient formation of nanomaterials with controlled size, shape, and composition. The book chapter on ultrasound-based sonochemical synthesis of nanomaterials is crucial for advancing the field of nanotechnology. It not only provides a comprehensive review of the principles, techniques, and applications of sonochemical synthesis but also addresses the current challenges and future directions. This chapter begins with an overview of the basic principles of ultrasound and cavitation, followed by a detailed discussion on the selection of precursor materials and solvents, and the various parameters influencing the synthesis process. The key advantages of sonochemical methods, such as mild reaction conditions, scalability, versatility, and enhanced reactivity, are highlighted. Further, the chapter covers a wide range of applications for sonochemically synthesized nanomaterials, including catalysis, biomedical uses, energy storage, and environmental remediation. Finally, the chapter addresses the current challenges in the field, such as achieving uniform size and shape distribution, optimizing large-scale production, and managing energy consumption. Future directions and potential advancements in ultrasound-based sonochemical synthesis are also discussed, emphasizing the ongoing research efforts to overcome these challenges and fully harness the potential of this innovative technique.