Nanomaterials (NMs) have emerged as potential new platforms in cancer therapy to improve drug delivery, offering significant advancements in mitigating the various hurdles related to traditional treatments. Their distinctive characteristics like high volume to surface area proportion, biocompatibility and functionalization for targeted delivery, put them as highly effective candidates for enhancing the effectiveness of various cancer therapies. Nanomaterials were engineered to precisely target tumor cells, enhanced drug loading, and facilitated controlled release, thereby curtailing side effects on non-cancer cells and improving therapeutic outcomes. Polymeric nanoparticles, liposomes, dendrimers, micelles, and quantum dots, etc. have shown promising role in treating cancer owing to narrow down the drug effects to tumor sites and their multifunctionality. By targeting key components of tumor microenvironment (TME), such as immune cells, fibroblasts, tumor vasculature and the extracellular matrix (ECM), NMs can improve drug penetration, retention, and stimulate immune responses for more effective treatment. Our chapter described the summary of various nanomaterials used in cancer therapy, their role in modulating the TME and immunotherapy, as well as the challenges and future perspectives of their clinical application. Nanomaterials therefore have great potential to improve cancer treatment and influence the direction of cancer therapy in the future.