John Henderson Blackley (born 12 May 1948) is a Scottish football coach and former player.
Blackley made 279 appearances at centre-half for Hibernian and also represented Newcastle United, Preston North End and Hamilton Accies. He won seven Scottish international caps and represented his country in the 1974 FIFA World Cup.
Blackley began a mangerial career with Hamilton in 1982, before taking charge of another former club, Hibs, between 1984 and 1986. His final managerial role was at Cowdenbeath, which he left to become Gordon Wallace’s assistant at Dundee.