The present disclosure relates to a heat transfer member capable of preventing propagation of thermal runaway and a battery module including the same, and more particularly, to a heat transfer member capable of preventing propagation of thermal runaway in which heat or flame is propagated due to ignition or the like of at least one battery cell in a battery module, and a battery module including the same. According to the present embodiment, a heat transfer member provided in contact with a cooling member in a battery module or a stack composed of a plurality of battery cells includes a thermally expandable material having a thermal expansion initiation temperature of 90 to 150° C.