In 1960, as the defending Canadian amateur champion, Johnny Johnston played the American champion, Jack Nicklaus, in Ottawa. This was the first of five occasions that they were matched before Nicklaus turned pro in 1962. As a result of his successful career, Johnston received personal invitations to play in both the Bob Hope and the Bing Crosby Invitational tournaments.

Johnston began his golf career in 1953 by winning the first of several New Westminster City amateur championships. He was a member of eight Hamber Trophy-winning BC Amateur teams between 1954-66. He was a member of ten Willingdon Cup teams including victories in 1959, 1961, and 1967). He was also a member of Canada’s 1960 and 1968 World Cup teams, the 1960 Canadian Commonwealth team, and a member of four America’s Cup teams in 1958, 1961, 1965, and 1967, of which the 1965 team was victorious.

Johnston was a medallist at the 1960 Canadian amateur championships, finishing with the lowest score for two rounds in Willingdon Cup play. He placed second and “Low Amateur” at the 1965 BC Open and won the New Westminster and Vancouver City championships. In 1966, he was named “Low Amateur” at the Canadian Open and won the BC Amateur championships.

In 1967, he won the BC Open, the New Westminster City championships, and the Mexican Amateur championship. That same year he was a member of the Canadian Commonwealth team which placed third, an event hosted by Canada at the Victoria Golf Club. He also won the 1967 Penticton Open in his first of six wins: 1967-70, 1972, 1974.