Abstract The concept of entropy stabilized complex materials provides a novel direction for the design and engineering of breakthrough materials to be used in extreme environments and particularly in advanced nuclear reactors. While still in its infancy, the use of high entropy materials (HEMs) in nuclear fusion/fission reactors is extremely promising. This mini review first gives a brief introduction to advanced nuclear reactors and their material requirements. Next, it summarizes recent advances in irradiation behaviors of high entropy alloys (HEAs). Additionally, challenges and perspectives regarding the irradiation behavior of HEAs and potential research directions are deduced.