Cancer is the leading cause of mortality worldwide with more than 10 million deaths in 2020, hence pose a significant health burden. Several treatment options are available for the treatment of cancer, among which cancer immunotherapy has gained attention in past few years. During immune-therapy, the host immune responses activated against cancer cells. However, the success rate of cancer immunotherapy is limited due to poor therapeutic targeting and undesirable side effects. To confer the specificity, nanoparticles (NPs) mediated immunotherapy has been emerged as promising platforms for revolutionizing cancer treatment. The current chapter explores the diverse applications of NPs in cancer immunotherapy as carriers for immunotherapeutic agents, immune-modulators for natural killer cells, T cells, and dendritic cells. Various types of NPs are explored for immune-stimulation, with strategies aimed at optimizing their immune-stimulatory effects. In conclusion, the clinical translation of nano-immunotherapy holds immense potential in revolutionizing cancer treatment paradigms.