Immunosenescence represents a natural process of immune degeneration that occurs with aging. Although this process is a common phenomenon in elderly patients, it extremely gets involved in tumor development and affects the clinical efficacy of cancer immunotherapy. Emerging studies demonstrate that improving immunosenescence may greatly enhance the efficacy and prognosis of cancer immunotherapy in elderly patients. However, limited clinical and preclinical studies have addressed immunosenescence as a therapeutic consideration, and the challenges of traditional cancer immunotherapy remain to be resolved. Nanomedicine, integrating nanotechnology and medicine, employs advanced nanomaterials and targeted drug delivery systems to achieve optimal region-specific biodistribution and therapeutic efficacy. This review systematically describes the various elements of immunosenescence and the impact on the vicious cycle between them and the tumor microenvironment. Meanwhile, based on a comprehensive understanding of the importance of immunosenescence in cancer formation and progression among elderly populations and the advantages of nanomedicine, we detail the feasibility of nanomedicine in improving immunosenescence to enhance cancer immunotherapy. Furthermore, this review also systematically discusses the synergistic mechanisms and clinical application prospects of nanomaterials with novel immunotherapy technologies, while also providing insights into the challenges and future directions in this field. In conclusion, this review provides comprehensive insights into the design and development of nanodrugs for improving immunosenescence, aiming to assist scientists who wish to expand their research scope and engage in this interdisciplinary field.