Supported‐metal catalysts, pivotal for industrial applications, have their catalytic properties affected by metal‐support interactions (MSIs), which notably influence both their electronic and geometric characteristics. Therefore, understanding internal and external factors that influence MSIs is crucial for the rational design of catalysts. Our minireview focuses on the effects of the gas environment on the MSIs, particularly the morphological changes in metal nanoparticles, the migrating behavior of reducible supports (strong metal‐support interaction), and the compositional rearrangement of the catalysts (reactive metal‐support interaction). Future directions are suggested to elucidate the fundamental aspects of gas environment induced structural reconstruction of catalysts, including the quantitative analysis of dynamic behavior of both the surface and interface, atomic‐level insights into the structures of the metal, support, and interface under pertinent conditions through advanced in situ/operando characterization, and the in situ manipulation of structural reconstruction. This minireview examines how gas environments impact metal‐support interactions in supported‐metal catalysts. It discusses morphological changes in metal nanoparticles, behavior of reducible supports, and compositional rearrangement of catalysts under various conditions. The review suggests future research for understanding gas‐induced structural reconstruction in catalysts, emphasizing the need for advanced in situ/operando characterization and quantitative analysis of dynamic surface and interface behaviors.