Cryptococcus neoformans is considered a critical fungal pathogen by the World Health Organization and developing a vaccine for cryptococcosis is a top priority. Here, we employed mRNAs encoding an antigen(s) packaged in lipid nanoparticles (LNPs) to develop vaccines for cryptococcosis. Remarkably, when coupled with capsule adjuvant, vaccination with CDA1-LNPs protected the vast majority of mice from the otherwise lethal cryptococcosis. These results support the promise of mRNA-LNP vaccines against fungal diseases.