Blackley made 279 appearances at centre-half for Hibernian and also represented Newcastle United, Preston North End and Hamilton Academical.
He won seven Scottish international caps and represented his country in the 1974 FIFA World Cup, playing in the 2–0 win against Zaire.
Blackley has since worked at several clubs with Paul Sturrock, including St Johnstone, Dundee United, Plymouth Argyle twice, Sheffield Wednesday and Swindon Town.
Blackley was part of a successful coaching trio alongside Paul Sturrock and Kevin Summerfield that saw them achieve four promotions in six seasons.
Blackley and Summerfield left Plymouth in October 2009 after being advised their contracts, which were due to expire at the end of the 2009–10 season, were not going to be renewed.