Materials in Nuclear Energy Systems 2025 (MiNES 2025) is the fourth installment of this highly successful conference series. MiNES 2025 serves as the professional destination for the fission reactor materials community where attendees will share the latest research and developments specific to the field. The MiNES series is an outgrowth of the TMS Microstructure Processes in Irradiated Materials Symposium and the American Nuclear Society (ANS) Nuclear Fuel and Structural Materials Symposium, with both societies invested in the quality and success of the MiNES symposium series. The conference takes place biannually, with TMS and ANS alternating sponsorship.