Ross Johnstone (born April 7, 1926) is a retired Canadian professional ice hockey defenceman who played 42 games in the National Hockey League with the Toronto Maple Leafs. He was born in Montreal, Quebec. In 1945 his name was put on the Stanley Cup.
He played junior hockey for the Toronto Marlboros and the Oshawa Generals, playing in the 1942-43 Memorial Cup Final with the Generals. Johnstone turned pro the following season, splitting his time between the Toronto Maple Leafs and the Providence Reds. In 1944-45 he played in 24 games for the Leafs, winning the Stanley Cup.
He spent the next seven years in the minor pros.
In the NHL Johnstone played in 42 games, all with Toronto, and scored 5 goals and 4 assists.