Swine influenza viruses (SIVs) are complex and constantly evolving pathogens that pose serious economic and zoonotic threats. This chapter reviews current understanding of SIVs, including their virology, epidemiology, evolution, diagnosis, and control strategies. SIVs exhibit high genetic diversity, with main subtypes such as H1N1, H1N2, and H3N2 continuing to circulate globally through ongoing antigenic shifts and reassortments. Mechanistic studies have revealed the functions of viral structural and nonstructural proteins, which are crucial for assessing replication, pathogenicity, and host adaptation. Epidemiological surveillance shows specific geographical trends in viral prevalence and evolution, supported by phylogenetic data indicating frequent transmission among humans, pigs, and birds. Advanced molecular techniques improve detection sensitivity and strain differentiation, benefiting outbreak control. The immune response to SIV infection involves complex interactions between the host and the virus, which guide vaccine development. Current prevention strategies include various vaccines, from inactivated forms to nucleic acid-based and universal vaccines. However, significant challenges remain in achieving broad-spectrum immunity due to the virus’s rapid evolution. Future efforts should prioritize developing cross-protective vaccines, improving diagnostic technologies, and implementing One Health approaches to better manage the increasing zoonotic risks of influenza A viruses (IAVs) in swine.