This study is based on advancements in immunotherapy using nanomedicine. Nanomedicine involves the application of nanotechnology in the field of healthcare. The unique properties of nanoparticles, such as a high surface area, render them suitable for drug loading and targeted delivery. Nanomedicine formulations can be used with drugs, CAR-T cells, and antibodies to address immunotherapy limitations such as drug resistance, dosage optimization, and efficient cellular uptake. Nanomedicine formulations can also be incorporated with cancer proteins to design a nano vaccine. The comprehensive analysis of various studies revealed a significant enhancement in the effectiveness of immunotherapy with nanomedicine in the treatment of cancer. The culmination of this study’s literature review underscores the impact of nanomedicine on enhancing the efficacy of immunotherapy as demonstrated in various treatment outcomes. This establishes a robust foundation for future nanomedicine-based immunotherapy development, which needs further research.