Chilling injury (CI) remains a critical postharvest challenge for mangoes during cold storage, often resulting in quality deterioration and reduced marketability. This study evaluated the efficacy of carboxymethyl cellulose-loaded liposomes (L-CMC) and GABA-enriched carboxymethyl cellulose-loaded liposomes (L-CMC-GABA) as novel edible coatings to alleviate CI symptoms and extend fruit storability. Mangoes were stored at 5 °C for 28 days, with assessments conducted at 7-day intervals. The L-CMC-GABA treatment markedly reduced CI symptoms; including pitting, flesh browning, malondialdehyde accumulation, and electrolyte leakage compared to untreated controls. Enhanced activities of antioxidant enzymes (SOD, GR, CAT, POD, and APX) were observed, indicating reduced oxidative damage and improved membrane stability. Furthermore, L-CMC-GABA modulated GABA metabolism by enhancing the activities of glutamate decarboxylase, GABA transaminase, and succinic semialdehyde dehydrogenase, contributing to improved chilling tolerance. The treatment also preserved fruit firmness and cell wall structure by suppressing the activities of cell wall-degrading enzymes such as polygalacturonase, β-galactosidase, and pectin methylesterase. The liposomal encapsulation facilitated a sustained release of GABA, maximizing its protective role during storage. Overall, L-CMC-GABA proved to be a highly effective postharvest strategy, significantly enhancing mango shelf life and maintaining quality under chilling conditions.