The development of vaccines has entered a new era with the advent of nanotechnology, particularly through the utilization of nanoparticles. This review focuses on the role of nanoparticles in enhancing the efficacy and stability of mRNA vaccines. Nanoparticles, owing to their unique properties such as high surface area, tunable size, and their ability to be functionalized, have emerged as powerful tools in vaccine development. Specifically, lipid nanoparticles (LNPs) have revolutionized the delivery of mRNA vaccines by protecting the fragile mRNA molecules and facilitating their efficient uptake by cells. This review discusses the various types of nanoparticles employed in mRNA vaccine formulations, including lipid-based, polymer-based, and inorganic nanoparticles, highlighting their advantages and limitations. Moreover, it explores the mechanisms by which nanoparticles improve immune responses, such as enhanced antigen presentation and the prolonged release of mRNA. This review also addresses the challenges and future directions in nanoparticle-based vaccine development, emphasizing the need for further research to optimize formulations for broader applications. By providing an in-depth analysis of the current advancements in and potential of nanoparticles in mRNA vaccines, this review aims to shed light on their critical role in combating infectious diseases and improving public health outcomes.