Cancer treatment has been revolutionized by immunotherapy and nanomedicine, offering innovative strategies to overcome the tumor microenvironment (TME) complexities. However, challenges such as therapeutic resistance, off-target effects, and immune suppression necessitate advanced delivery systems and combination approaches. Recent advancements in nanoparticle-based therapies, biomimetic platforms, and personalized immunotherapy provide promising solutions to enhance therapeutic efficacy while minimizing systemic toxicity. This review explores recent nanoparticle-mediated immunotherapy developments, highlighting strategies to optimize drug delivery, remodel the TME, and improve patient-specific treatment outcomes. A comprehensive review of recent literature focused on nanoparticle-based drug delivery, stimuli-responsive systems, biomimetic nanoplatforms, and personalized immunotherapy approaches. The effectiveness of combination therapies integrating physical and immunological strategies was also analyzed. Nanoparticle-mediated immunotherapy enables precise targeting and controlled drug release, significantly improving therapeutic outcomes. Biomimetic nanoplatforms enhance immune modulation and drug bioavailability, while personalized immunotherapy, guided by predictive biomarkers, tailors treatment to individual patients. Advanced nanomedicine strategies, including TME remodeling, targeted genome editing, and combination immunotherapies, offer promising avenues for overcoming limitations in conventional cancer treatments. Future research should optimize nanoformulations, integrate multi-modal treatment strategies, and refine biomarker-driven personalization to enhance clinical outcomes.