Abstract: The potential risk of radiation exposure is increasing because of the widespread use of nuclear technologies in the fields of medicine, science, technology, and military and various industries. Moreover, safe and effective radioprotective agents are lacking. Polypeptides play a vital regulatory role in various living processes. Polypeptide drugs are highly selective, efficacious, and safe, and modifications are easy to incorporate for the optimization of peptide functionality. Hence, many studies on radioprotective polypeptides have been conducted. Here, we provide an overview of peptides as radioprotective agents, particularly their molecular characteristics, design ideas, and the specific therapeutic effects of potential radioprotective peptides, aiming to lay the groundwork for the research of radioprotective polypeptides.