Swine corticosteroid-binding globulin (CBG), also known as serpin A6, is a plasma glycoprotein primarily synthesized in the liver that binds and transports glucocorticoids—particularly cortisol—in pigs (Sus scrofa). CBG regulates the bioavailability of circulating cortisol by maintaining a reservoir of bound hormone, thereby controlling the fraction of free, biologically active cortisol that can interact with glucocorticoid receptors in target tissues. Under basal physiological conditions, the majority of circulating cortisol in swine is bound to CBG, with only a small proportion remaining free and active. During stress, inflammation, infection, or tissue injury, changes in CBG concentration or proteolytic cleavage of CBG can alter free cortisol levels, contributing to modulation of the hypothalamic–pituitary–adrenal (HPA) axis response. In veterinary and translational research, swine CBG is particularly relevant in studies of stress physiology, animal welfare, immune–endocrine interactions, metabolic regulation, transport stress, and inflammatory disease models. Because pigs share important physiological similarities with humans, characterization of swine CBG provides valuable insight into glucocorticoid regulation, stress adaptation, and endocrine–immune balance in both agricultural and biomedical research settings.