Gamma-aminobutyric acid (GABA) plays a decisive role in plant growth regulation and stress adaptation, encouraging its exogenous administration for augmented crop performance and productivity. Exogenous GABA application proficiently modulates plant morphology under various environmental conditions. Its application influences root development, shoot architecture, leaf morphology, and overall biomass accumulation. GABA promotes root elongation, lateral root formation, and root hair development, facilitating enhanced water and nutrient uptake. In shoots, it regulates stem elongation, leaf expansion, and chlorophyll biosynthesis, leading to improved photosynthetic efficiency and biomass production. GABA application secures stress-induced morphological changes, mitigating the adverse effects of drought, salinity, and temperature extremes. By modulating cellular signalling pathways and interacting with plant hormones, GABA enhances plant structural resilience and adaptability. Understanding these morphological effects highlights GABA’s potential as a tool for crop improvement, particularly in the face of global climate challenges.