Cancer immunotherapy has revolutionized oncology, offering new hope for patients with previously incurable cancers. However, solid tumors remain a significant challenge due to immune evasion, therapeutic resistance, and the immunosuppressive tumor microenvironment. Exosomes, a specialized subset of extracellular vesicles, have emerged as promising tools in cancer therapy owing to their unique role in intercellular communication and immune modulation. These vesicles transport antigens, major histocompatibility complex (MHC) molecules, and immune-modulatory cargo, positioning them as potential platforms for cancer vaccines, drug delivery systems, and combinatorial therapies. Advances in engineered exosomes have improved drug bioavailability, tumor targeting, and immune stimulation, showcasing their potential in personalized medicine. This review highlights their multifaceted role in the tumor microenvironment, and their mechanisms of action in solid cancer therapy. Additionally, we discuss emerging strategies to overcome clinical and technical hurdles, paving the way for novel and effective cancer treatments.