Nanomaterials have emerged as a tool in precision oncology, enabling significant advancements in both cancer therapy and diagnostics. This chapter explores the role of various nanomaterials, including metallic, polymeric, lipid-based, carbon-based, and hybrid nanoparticles, in revolutionizing cancer treatment. By exploiting the unique properties of these nanoparticles, researchers have developed targeted drug delivery systems, photothermal and photodynamic therapies, radiosensitizers for enhanced radiotherapy, and immunomodulatory approaches, all contributing to more effective and personalized cancer care. Moreover, theranostic nanomaterials—those that combine diagnostic and therapeutic functions—allow for real-time monitoring of treatment efficacy while simultaneously delivering targeted therapies. Nanomaterials are also key to the development of advanced biosensing platforms for early cancer detection, leveraging their ability to enhance the sensitivity and specificity of biomarker detection, enabling improved diagnostic accuracy. The integration of nanomaterials with imaging modalities such as MRI, CT, PET, and optical imaging has opened up new avenues for noninvasive monitoring of tumors and assessing treatment responses. Furthermore, the advent of microfluidic systems and lab-on-a-chip devices incorporating nanomaterials has accelerated the progress of personalized medicine by enabling rapid, multiplexed biomarker detection from small sample volumes. While these innovations offer immense promise, challenges remain, including concerns around toxicity, scalability, regulatory approval, and the high cost of manufacturing. The chapter also discusses the emerging trends of smart, stimuli-responsive nanomaterials, as well as the integration of artificial intelligence and machine learning in nanomaterial design and optimization, which are poised to further enhance the precision and effectiveness of cancer therapies. Ultimately, nanomaterials represent a crucial step toward personalized, targeted, and minimally invasive cancer treatments, with the potential to improve patient outcomes and revolutionize cancer care in the future.