Hydrostatic pressure provides a powerful yet underexploited parameter for regulating supramolecular recognition and signaling in solution. Because pressure directly couples to changes in molar volume, it enables quantitative perturbation of noncovalent interactions, conformational equilibria, solvation structures, and excited-state relaxation pathways that define the function of supramolecular chemosensors. Across diverse host architectures, pressure shifts pre-existing distributions between compact and expanded conformers, alters local polarity and solvation, and modulates the thermodynamics of guest association through characteristic reaction volumes. Chiral assemblies further translate pressure into changes in helicity and stereoselectivity, revealing how solvation and desolvation events govern enantioselective recognition under isotropic compression. In excited states, pressure influences emission color, intensity, and lifetimes by modifying chromophore orientation, packing, and solvent reorganization. Taken together, these observations establish general principles for pressure-responsive supramolecular systems, including volumetric coupling, solvent-driven modulation, conformational adaptability, and reversible reorganization of weak interactions. These concepts provide a unified framework for designing pressure-sensitive supramolecular chemosensors that convert mechanical stimuli into optical or structural outputs.