Blackley made 279 appearances at centre-half for Hibernian, being promoted to the manager's position at Easter Road in 1984. He won seven Scottish international caps and represented his country in the 1974 FIFA World Cup, playing in the 2–0 win against Zaire in host country West Germany.
National team Scotland
Polmont born John Blackley, a Bob Shankly signing from local side Gairdoch United in the mid 1960's, played the first of his 262 league games for the club during the 1967-68 season. Soon he would be a first team regular, but like several other players then at Easter Road, it was only under the guidance of manager Eddie Turnbull his career truly prospered. Yet another of the legendary Tornado's, the talented Blackley won his first of his seven full caps, all with Hibs, in the return World Cup qualifier against Czechoslovakia in Bratislava in October 1973.
A League Cup and Drybrough Cup winner at Easter Road, Blackley, who played against Zaire in the 1974 World Cup Finals in Munich, made his final appearance for Scotland against Sweden at Hampden in April 1977. The intelligent and talented player, who Turnbull once described as sometimes having too much football, on account of his often-leisurely use of the ball in his own penalty area, remained at Easter Road for eleven seasons before signing for Newcastle United in 1977.
After a couple of seasons at St James Park he moved to Preston North End before returning to Scotland with Hamilton Academicals. Well past his best he made a return to Easter Road in 1983, primarily as assistant to manager Pat Stanton, but emergency saw him make a further 16 Premier League appearances that season. After Stanton's resignation in 1984, chairman Kenny Waugh appointed Blackley Hibs manager but he too resigned a short while later.