2010-11: Josh Ho-Sang skated for the Toronto Marlies bantam and midget teams and joined the midget AAA team for its championship run at the 2011 OHL Cup. In seven games at the tournament he scored 4 goals with 5 assists and had 2 penalty minutes.
2011-12: Ho-Sang was dominant in Ontario midget hockey skating alongside 1997-born forward Connor McDavid for the Toronto Marlies. In 30 regular season games he scored 31 goals with 48 assists and had 24 penalty minutes. The Marlies reached the OHL Cup championship game against the Don Mills Flyers and in five games Ho-Sang scored 2 goals with 4 assists and 19 penalty minutes. Ho-Sang was the fifth player taken in the 2012 OHL Priority Draft when he was selected in the first round by Windsor.
2012-13: Ho-Sang skated in 63 OHL games for Windsor as a 16-year-old and played for Canada Ontario in the 2013 U17 World Hockey Challenge. He scored 14 goals with 30 assists and was -23 with 22 penalty minutes. One of the OHL's youngest teams, the Spitfires missed the playoffs; finishing last in the West Division. Ho-Sang scored 3 goals with 2 assists for Canada Ontario in five games at the WHC.
2013-14: Ho-Sang returned to Windsor and was part of an early resurgence for the Spitfires. He was selected to compete for Team Orr in the 2014 CHL/NHL Top Prospects Game.