Recent advances in nanotechnology have significantly contributed to the development of innovative tools for both cancer diagnosis and treatment. Nanomaterials serve as the fundamental building blocks of nanotechnology, offering unique properties not found in bulk materials. Through functionalization, these nanomaterials can be modified to enhance and control their properties, making them suitable for various medical applications. These engineering nanostructures with surface or bulk functionalization have gained multifunctional capabilities, paving the way for advancements in biomedical fields such as biosensing, drug delivery, imaging, medical implants, cancer treatment, and tissue engineering. This chapter gives a comprehensive overview of recent research in functionalized nanomaterials for biomedical applications. It covers various types of nanomaterials and explores surface functionalization strategies. Furthermore, with their potential in advancing healthcare technologies, these versatile nanomaterials offer promising solutions across various medical applications.