Posted in Government & Military, Organizations, Science, Sports YSO stands for Yellow Springs, Ohio YSO stands for Young Stellar Object YSO stands for Yale Symphony Orchestra YSO stands for Yamagata Symphony Orchestra (Japan) YSO stands for Youth Service Officer YSO stands for Youth Soccer Organization (various organizations) YSO stands for Yttrium Oxyorthosilicate YSO stands for Youngstown Symphony Orchestra (Youngstown, OH) YSO stands for York Symphony Pops Orchestra