The article reviews the role of nanoparticles in remodeling the tumor microenvironment (TME) and enhancing cancer immunotherapy. It highlights the challenges in clinical delivery of immunomodulatory compounds and the importance of the TME, which includes macrophages, fibroblasts, and immune cells, in modulating immune responses. Nanoparticles engineered to reshape the TME have shown promising results in improving immunotherapy by facilitating targeted delivery and immune modulation. These nanoparticles can suppress fibroblast activation, promote M1 macrophage polarization, aid dendritic cell maturation, and encourage T cell infiltration. Biomimetic nanoparticles enhance immunotherapy by increasing the internalization of immunomodulatory agents in immune cells. Exosomes, whether naturally secreted or bioengineered, have also been explored to regulate the TME and immune-related cells. Stimuli-responsive nanocarriers, activated by pH, redox, and light conditions, exhibit potential to accelerate immunotherapy. Co-application of nanoparticles with immune checkpoint inhibitors is an emerging strategy to boost anti-cancer immunity. Nanoarchitectures are promising structures in vaccine development due to their ability to induce long-term immunity. The review underscores the critical role of nanoparticles in overcoming current challenges and driving advancements in cancer immunotherapy and TME modification.The article reviews the role of nanoparticles in remodeling the tumor microenvironment (TME) and enhancing cancer immunotherapy. It highlights the challenges in clinical delivery of immunomodulatory compounds and the importance of the TME, which includes macrophages, fibroblasts, and immune cells, in modulating immune responses. Nanoparticles engineered to reshape the TME have shown promising results in improving immunotherapy by facilitating targeted delivery and immune modulation. These nanoparticles can suppress fibroblast activation, promote M1 macrophage polarization, aid dendritic cell maturation, and encourage T cell infiltration. Biomimetic nanoparticles enhance immunotherapy by increasing the internalization of immunomodulatory agents in immune cells. Exosomes, whether naturally secreted or bioengineered, have also been explored to regulate the TME and immune-related cells. Stimuli-responsive nanocarriers, activated by pH, redox, and light conditions, exhibit potential to accelerate immunotherapy. Co-application of nanoparticles with immune checkpoint inhibitors is an emerging strategy to boost anti-cancer immunity. Nanoarchitectures are promising structures in vaccine development due to their ability to induce long-term immunity. The review underscores the critical role of nanoparticles in overcoming current challenges and driving advancements in cancer immunotherapy and TME modification.