Charlie Johnstone was widely acknowledged as one of the greatest athletes in the early history of sport in Manitoba. Although he was also an accomplished curler and gymnast, Johnstone first gained prominence as a lacrosse player when he played the position of cover-point for the famous 90th Lacrosse Club that dominated provincial play from 1891 to 1895. Johnstone was named to an all-Winnipeg team which played the world champion Montreal Shamrock club.
Johnstone enjoyed an illustrious hockey career as a member of the Winnipeg Victorias Hockey Club from 1897 to 1902. In his position as rover, Johnstone revolutionized the sport of hockey with a combination of skill and fitness that made the Victorias perennial challengers for the Stanley Cup around the turn of the century. Johnstone was an important member of the squads that won the Cup in 1901 and defended the title in 1902.
It was in the sport of rowing that Johnstone made the greatest impact. In 1896, he was a crew member of the Winnipeg Rowing Club's winning team at the International Rowing Regatta in Minneapolis, Minnesota, USA and won both senior singles races at the American National Regatta in Worcester, Massachusetts, USA. That same year, Johnstone also won at the Canadian Regatta at Brockville, Ontario.
In 1897, Johnstone won singles and doubles titles at the American National Regatta in St. Paul, Minnesota, USA and was a member of victorious crews at U.S. national rowing regattas from 1901 to 1903. Towards the end of his competitive career, Johnstone served as captain and coach of the Winnipeg Rowing Club from 1903 to 1907 and coached many senior crews in the 1930's. In total, Johnstone won seven American Sweep Oar championships, a feat matched by fellow Manitoba Sports Hall of Fame member Conrad Riley.
Charlie Johnstone is also a member of the Manitoba Hockey Hall of Fame.