Swine Interleukin-13 (IL-13) is a Th2-associated cytokine produced primarily by activated CD4⁺ T helper 2 (Th2) cells and other type 2 immune populations in pigs (Sus scrofa domesticus), where it plays an important role in regulating mucosal immunity, alternative macrophage activation, and tissue remodeling. IL-13 signals through receptor complexes composed of IL-13Rα1 and IL-4Rα, activating JAK/STAT6 pathways that promote IgE-associated responses, mucus production, modulation of pro-inflammatory cytokine signaling, and support of wound healing processes. In swine health, IL-13 is particularly relevant in responses to gastrointestinal and respiratory parasitic infections, where Th2 polarization aids parasite clearance and mucosal repair. IL-13 may also influence immune regulation during viral infections such as porcine reproductive and respiratory syndrome virus (PRRSV) and swine influenza by shaping the balance between Th1 and Th2 responses. While protective in controlling inflammation and supporting tissue repair, excessive or prolonged IL-13 activity may contribute to airway remodeling or fibrotic changes. As a biomarker of type 2 immune activation, swine IL-13 is important in studies of vaccine efficacy, host–parasite interactions, and immune resilience in production systems. In translational research, pigs serve as valuable large-animal models due to physiological similarities to humans, and characterization of swine IL-13 supports comparative investigations into Th2-mediated inflammation, fibrosis, and cytokine-targeted therapeutic strategies.