Exogenous gamma-aminobutyric acid (GABA) application impacts plant physiological and biochemical processes that manifest as improved growth and yield. GABA regulates metabolism through the GABA shunt, enhancing energy production and supporting cell proliferation. It maintains ion homeostasis/cellular membrane integrity, modulates root and shoot development, and improves photosynthetic efficiency. Its interaction with plant hormones further enhances resilience and reproductive success. As a result, GABA-treated plants exhibit stress resilience together with high seed germination and biomass accumulation that translate into augmented flowering/fruit set and fruit/grain yield/quality. The mode of GABA applications in agriculture includes foliar sprays, seed priming, and soil/hydroponic incorporation to boost plant performance. The chapter highlights GABA’s potential as a sustainable agricultural tool for enhancing productivity and stress resilience.