Graphene oxide (GO) is a carbon-based nanoparticle that has garnered significant interest across various fields over the last decade. GO exhibits exceptional physical and chemical characteristics, making it highly promising in the realm of biomedicine. The application of GO nanostructures shows potential in the field of oncology, facilitating the accurate delivery of medicines and genetic material to specific locations. This chapter delves into the innovative application of GO nanomaterials in cancer therapy, focusing on their multifunctional capabilities. GO’s unique structure, characterized by a large surface area and functional groups, allows for effective drug and gene delivery, enhancing tumor targeting and treatment efficiency. The chapter also explores GO’s potential in phototherapy, its role in stimulating immune responses, and the challenges associated with its biocompatibility and toxicity.