The Spanish Flu Pandemic of 1918, one of history’s deadliest disease outbreaks, affected millions worldwide. Emerging during World War I, the H1N1 influenza virus spread swiftly due to global troop movements. Unlike typical flu strains, it disproportionately affected healthy young adults, causing rapid deterioration and death. With limited medical understanding, healthcare systems struggled to cope. The pandemic’s toll was staggering, claiming an estimated 50 million lives globally. Despite its name, its origins remain debated. The Spanish Flu’s impact accelerated advancements in virology, influencing future pandemic preparedness and underscoring the devastating potential of infectious diseases on a global scale.