The cGAS-STING signaling pathway plays a crucial role in enhancing antitumor immunity by activating innate immune responses. However, systemic administration of current STING agonists faces challenges such as low bioavailability and potential adverse effects. Nanotechnology-based strategies have emerged as a promising approach to modulate the tumor microenvironment (TME) and improve immunotherapeutic responses. This review explores nanoparticles (NPs) designed to encapsulate STING agonists, highlighting their benefits, including improved biocompatibility, enhanced tumor penetration, and efficient intracellular delivery. The review also discusses the immunomodulatory impacts of STING-NPs on the TME, including increased secretion of pro-inflammatory cytokines, dendritic cell activation, cytotoxic T cell priming, macrophage re-education, and vasculature normalization. Additionally, the review offers insights into co-delivered nanoplatforms involving STING agonists alongside antitumor agents such as chemotherapeutic compounds, immune checkpoint inhibitors, antigen peptides, and other immune adjuvants, demonstrating their versatility in inducing immunogenic responses within the TME and enhancing the potential for antitumor immunotherapy.The cGAS-STING signaling pathway plays a crucial role in enhancing antitumor immunity by activating innate immune responses. However, systemic administration of current STING agonists faces challenges such as low bioavailability and potential adverse effects. Nanotechnology-based strategies have emerged as a promising approach to modulate the tumor microenvironment (TME) and improve immunotherapeutic responses. This review explores nanoparticles (NPs) designed to encapsulate STING agonists, highlighting their benefits, including improved biocompatibility, enhanced tumor penetration, and efficient intracellular delivery. The review also discusses the immunomodulatory impacts of STING-NPs on the TME, including increased secretion of pro-inflammatory cytokines, dendritic cell activation, cytotoxic T cell priming, macrophage re-education, and vasculature normalization. Additionally, the review offers insights into co-delivered nanoplatforms involving STING agonists alongside antitumor agents such as chemotherapeutic compounds, immune checkpoint inhibitors, antigen peptides, and other immune adjuvants, demonstrating their versatility in inducing immunogenic responses within the TME and enhancing the potential for antitumor immunotherapy.