Messenger RNA (mRNA) has broad potential as a therapeutic. Current clinical efforts are focused on vaccination, protein-replacement therapies, and treatment of genetic diseases. The clinical translation of mRNA therapeutics has been made possible through advances in the design of mRNA manufacturing, and intracellular delivery methods. However, broad application of mRNA is still limited by the need for improved delivery systems. In this review, we will discuss challenges for clinical translation of mRNA-based therapeutics with an emphasis on recent advances in biomaterials and delivery strategies, and present an overview of the applications of mRNA-based delivery for protein therapy, gene editing and vaccination.