The nonaqueous lithium–oxygen batteries have attracted considerable interest because of the ultrahigh theoretical capacity. However, the overpotential and cyclability issue of lithium–oxygen battery caused by interfacial issue limits its commercialization. To overcome these challenges, redox mediators, which are capable of charge transport on the electrode/electrolyte interfaces, are introduced to lithium–oxygen batteries to reduce overpotential. This review provides a detailed summary of the interfacial reaction mechanism and the influence of redox mediators on the electrode/electrolyte interfaces. Researches on suppressing redox mediators’ shuttle effect are also beneficial to enhance the electrochemical performance of lithium–oxygen batteries.