Swine Interferon-Alpha (IFN-α) is a type I interferon produced primarily by plasmacytoid dendritic cells and virus-infected cells in pigs (Sus scrofa domesticus), where it plays a central role in early innate antiviral defense. Upon binding to the type I interferon receptor complex (IFNAR1/IFNAR2), swine IFN-α activates JAK/STAT signaling pathways, leading to induction of interferon-stimulated genes (ISGs) that inhibit viral replication, enhance antigen presentation, and promote activation of natural killer (NK) cells and adaptive immune responses. IFN-α is critically involved in host responses to economically significant viral infections such as porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza virus, African swine fever virus (ASFV), porcine epidemic diarrhea virus (PEDV), and classical swine fever virus (CSFV), where viral immune evasion strategies often target type I interferon pathways to enhance replication and persistence. The magnitude and timing of IFN-α responses can influence disease severity, viral shedding, and vaccine efficacy. In translational research, pigs serve as valuable large-animal models due to physiological and immunological similarities to humans, and characterization of swine IFN-α supports studies of respiratory viral pathogenesis, antiviral therapeutics, vaccine development, and comparative type I interferon biology relevant to both veterinary medicine and human infectious disease research.