Hypoxic stress, often resulting from waterlogging or submergence, severely limits oxygen availability and disrupts cellular respiration, leading to metabolic imbalances and impaired growth. Emerging evidence highlights gamma-aminobutyric acid (GABA)‘s multifaceted role as a signaling molecule and metabolic intermediate that helps plants adapt to oxygen-deficient conditions. This chapter explores the biosynthesis and catabolism of GABA under hypoxic stress, emphasizing its involvement in energy homeostasis, redox balance, cytosolic pH regulation, and reactive oxygen species (ROS) scavenging. The interaction of GABA with hormonal signaling pathways, calcium signaling, and its contribution to stress memory and priming also elicits interest in hypoxia stress management. The GABA shunt pathway and its regulatory significance in enhancing plant resilience deserve special attention. Understanding the intricate GABA-mediated physiological and molecular mechanisms opens new avenues for developing hypoxia-tolerant crop varieties through genetic and metabolic engineering strategies.