<p>Metal halide perovskites have emerged as a cornerstone of next-generation optoelectronics, distinguished by their unique structural tunability and versatile functionalities. While chemical engineering has been extensively explored, high pressure provides a powerful thermodynamic dimension to manipulate lattice properties without chemical complexity. This review comprehensively analyzes high-pressure research on metal halide perovskites, bridging fundamental insights with engineering strategies. We examine structural evolution and optoelectronic responses in three-dimensional systems, followed by pressure-modulated excitonic behaviors in low-dimensional analogs. Beyond elucidating emergent phenomena and structure–property relationships, we highlight a paradigm shift toward pressure engineering—leveraging high-pressure discoveries to guide materials design. Key strategies include high-pressure structural mimicry, phase retention via pressure aging or steric effects, and heterostructure construction exploiting differential pressure responses. Finally, we provide an outlook on the future landscape of this field, emphasizing how the integration of advanced high-pressure techniques with simulation can accelerate the discovery of novel functional phases.</p> Graphical abstract <p></p>