Bernard Cairns was born on December 14, 1928 in Scotland. The wing half joined Scottish League club Airdrieonians from Duntocher Hibernians in August 1949.
Benny played in 136 league games and scored one goal for Airdrie before joining Dumbarton in 1955. He scored eight goals in 87 league games for Dumbarton.
On Wednesday March 19 in 1958 Benny arrived in Toronto to join Athletic Club Sparta. He quickly became a very popular player in the National Soccer League. Benny was noted for his energetic play. He was picked to play for the Ontario All-Stars against Heart of Midlothian on May 23. Hearts won the exhibition match 6-0 in front of 10,000 fans at Varsity Stadium.
Despite importing several players from the Scottish League Toronto Sparta finished in a lowly 11th place finish in the 15-team in the 1958 National Soccer League.
Sparta improved slightly in the 1959 National Soccer League season by finishing in eight place in the 14-team league. Benny was again picked to represent the Ontario All-Stars. On August 3 the All-Star team lost to Austrian club Rapid Wien.
The 5’9″ and 160 lbs. right half joined Toronto City before the start of the first season of the newly-created Eastern Canada Professional Soccer League in 1961. He replaced Northern Irish international Danny Blanchflower at right half when the former Tottenham Hotspur star left the club.
Benny remained with Toronto City until after the end of the 1962 Eastern Canada Professional Soccer League season.