The US won the Korean War and South Korea is a republic similar to ours.\\. Answer . \\. \\ The US did not win the Korean war. See "Who actually won the Korean War?" Better answer.\\. Answer . \\. \\ South Korea won the Korean War With the Help of Britain, Autralia and USA. Answer . Neither side won the Korean War, although at first it seems like North Korea was winning and then the South was. It was a tie because there was a stalemate for two years between the two sides.