 Before appointment to the Supreme Court, Geoghegan had spent eight years as a judge of the High Court, being nominated to that position by the short-lived Fianna Fáil-Labour coalition.Geoghegan has the special distinction of being the first son of a Supreme Court judge to follow in his father's footsteps.His father James Geoghegan was a Fianna Fáil TD for Longford–Westmeath from 1930 to 1937 and Minister for Justice, Attorney General, and a judge of the Supreme Court.