Leslie James Herron was born on 22 May 1902. He was educated at Sydney Grammar School and at the University of Sydney. He graduated in Law in 1924 and was admitted to the Bar on 28 August 1925.
He took silk in 1939 and was an acting Judge of the District Court for a time before being elevated to the Supreme Court bench on 10 February 1941.
He at various times held office as Chairman or President of the Australian and New South Wales Rugby Unions and he represented Australia on the International Rugby Board. He became President of the Australian Golf Club, the New South Wales Swimming Association, and of the Sydney Cricket Ground Trust.
Following a successful career in common law cases and a leading advocate in jury trials, Leslie Herron was appointed Chief Justice of New South Wales on 25 October 1962. He was appointed CMG in 1964 and KBE in 1966; and, being President of the State Division of the St John Ambulance Association he was further recognised with the honour of K St J In 1972 he was the second recipient of the degree of Doctor of Laws (
honoris causa) in the University of New South Wales.
In 1972 on attaining his 70th birthday Sir Leslie Herron was obliged to resign his office as Chief Justice after a judicial tenure spanning 31years. He continued as Lieutenant Governor and was Administrator of the State at the time of his death in hospital on 3 May 1973. He was survived by Lady Herron (Andree, daughter of Frank Leverrier, KC) and one daughter.
He held the view that his long experience with the daily work of the Court and his wide ranging interests, particularly in sport 'may have endowed me with that even greater quality of a judge, namely, sound judgment'. He saw the work of the Court 'to determine issues, criminal and civil, which arise in an orderly society between citizens in their daily commercial and social activities, and to preserve law and order in the community'.