Technological advances in the areas of nuclear systems, marine platforms, microelectronics, and aerospace applications, amongst others, are often constrained by limits on the performance of metals and alloys in these application environments. To meet these demanding applications, the properties of existing as well as emerging high-performance metals and alloys need to be explored, ultimately leading to the development of next generation of advanced materials. This symposium will focus on the properties of structural metals and alloys in the broad context of extreme environments. This topic area will include materials for radiation environments, mechanical extremes (high stress, strain or strain rate), high/low temperature, harsh environments that lead to chemo-mechanical coupling (e.g., stress corrosion cracking and hydrogen embrittlement), as well as size extremes (high surface to volume ratios). This symposium will cover a wide range of topics including the design of novel materials as well as material fabrication, characterization and performance evaluation. In addition, studies that use theoretical and computational methods to elucidate the properties of materials within these environments are also encouraged.