John Joseph Blayney (13 March 1925 – 17 June 2018) was an Irish rugby player, barrister and judge who served a Judge of the Supreme Court from 1992 to 1997 and a Judge of the High Court from 1973 to 1992. John Blayney was the son of Alexander Joseph Blayney, who was a prominent Dublin surgeon at Mater Hospital. Blayney has, on several occasions, sat on the bench for the European Court of Human Rights. Blayney played rugby union for Ireland, earning one cap in 1950 after running a 40-yard try against the Scottish side.