This symposium will focus on understanding the mechanical behavior, structural stability, transport properties, electronic/magnetic ordering, exciton generation/relaxation, and exotic properties of materials under extreme environments. Studies of materials under high pressure, high/low temperature, external electric/magnetic fields, strain loading, and fast dynamic pump-probe environments will be the major topics of this session. To generate extreme environments on earth, it is important to understand the behavior of materials used to achieve extreme environments and to develop new approaches to attaining the required properties under extreme conditions and to increase the available choice of materials, processing routes, and material dimensions available to designers and users for applications to the extreme environments. Extreme environments have been recognized as tools not only for probing material properties but also for controlling the stability of phases, and the microstructure and functionality of materials. Examples include 1) stabilization of ferromagnetic phases, 2) modification of texture in bulk and thin films during processing in metallic alloys and ceramics, 3) magnetic alignment and assembly of nanoparticles and polymers, 4) magnetic-field induced phase transformations, and 5) electromagnetic shaping of materials. The availability of new materials processed under extreme environments may lead to new science as well as new technologies and thus to better materials. Furthermore the large availability of advanced in-situ probe techniques (synchrotron, neutron, electron and optical probes) has been significantly accelerating the advancement of both theoretical modeling and experimental observations. We expect to bring together researchers from broader materials communities to explore the novel functional materials under these extreme conditions.