Posted in Government & Military, Internet Slang YO stands for York (postcode, United Kingdom) YO stands for Year Old YO stands for Yarn Over (knitting) YO stands for Years Old YO stands for Yugoslavia YO stands for Yoko Ono YO stands for Young Ones (Naturistische Activiteiten Vereniging) YO stands for Yeah, Okay YO stands for Youth Orchestra (various locations) YO stands for Youthful Offender YO stands for Young Offender (Ontario) YO stands for Yearly Output YO stands for Fuel Oil Barge (Self-Propelled) YO stands for District Barge, Fuel Oil (US Navy)