Nanotechnology has revolutionized cancer detection and treatment, overcoming limitations of conventional methods. Imaging, targeting, and therapy moieties can all be combined in multifunctional nanoparticle systems to deliver the imaging or treatment modalities to the tumor in a targeted manner. These nanostructures can be engineered to create smart drug delivery systems for effective distribution and combinatorial therapy. Nanostructures made of biomolecules are naturally multifunctional and have a variety of biological functions that can be investigated for use in cancer nanomedicine. The supramolecular characteristics of biomolecules can be carefully engineered to create smart drug delivery systems that enable effective drug distribution to specific areas of the body as well as combinatorial therapy in a single design. Nanotechnology has also increased the efficiency of cancer vaccines, highlighting the future of tumor immunotherapy. Nanomaterials are often used as anti-cancer drugs or anti-inflammatory drugs due to their biosafety potential and enhanced bioavailability. By delivering targeted antigens and adjuvants, nanomaterials can improve vaccination efficacy and safety, preventing rapid degradation and prolonging antigen retention in lymphoid and tumor cells. We examine both organic and inorganic multifunctional nanomaterials in this review, emphasizing particular multifunctional properties in the context of cancer targeting, therapy, and vaccinations.