Robert Randolph Garran was born in Sydney in 1867. He was educated at Sydney Grammar School and Sydney University. He had an illustrious academic career winning scholarships in classics, mathematics and for general proficiency. He obtained a Bachelor of Arts in 1888 and a Master of Arts (with first class honours and the University Medal in the School of Philosophy) in 1899. The University of Melbourne awarded him a Doctor of Laws in 1937, as did the Australian National University in 1951, and the University of Sydney in 1952.
 
Garran was admitted to the NSW Bar in August 1891 practicing mainly in the equity jurisdiction. The decade was, however, dedicated to the campaign for federation. He was a councillor of the Australasian Federation League of New South Wales and organised the League's delegations to the conferences about federation at Corowa and Bathurst, in 1893 and 1896 respectively. In 1897-1898 he attended the Australasian Federal Convention as Secretary to the NSW Premier George Reid. At Edmund Barton's request he became Secretary to the Drafting Committee of the Convention. Garran participated actively in the 1898 and 1899 referendum campaigns urging acceptance of the constitution bill. In 1899 he accompanied George Reid to the
Premiers' Conference as his counsellor on legal and constitutional matters.
 
Garran was appointed Secretary to the Attorney-General's Department and, simultaneously, Parliamentary Draftsman. The notification of appointment was not gazetted until July 1901, effective from June, however, Garran commenced working for the Commonwealth Public Service before it came into legal being. In 1916 he was appointed Solicitor-General.

Garran took part in several Australian delegations - to Imperial War Cabinet and War Conferences, to the Peace Conference, Imperial Conferences and the League of Nations' 11th Assembly.
 
Garran retired on 9 February 1932 as Solicitor-General, Secretary to the Attorney-General's Department and Parliamentary Draftsman.  
He retired to private practice and accepted a variety of official and community assignments. The British Government appointed him to chair the Indian Defence Expedition Tribunal in 1932. Between 1933-1937 he was chairman of the Book Censorship Board, and in 1937 he was appointed the Appeals Censor of the Literature Censorship Board. Between 1939 and 1956 he served as chancellor of the Anglican diocese of Goulburn. He was involved in the Society of Arts and Literature, and Canberra Musical Society, and the Canberra Rotary Club. He actively supported the establishment of a university in Canberra and worked on the Canberra University Association, chaired the Canberra University College Council and served on the Interim Council of the Australian National University.
           
Garran was appointed as a Companion of the Order of St Michael and St George (CMG) in 1901, was Knighted in 1917, received the Order of Knight Commander of the Order of St Micheal and St George (KCMG) in 1920, and the Knight Grand Cross of the Order of St Michael and St George (GCMG) in 1937.
 
Sir Robert Garran died on 11 January, 1957 in Canberra. He was the first Commonwealth Public Servant accorded a State funeral and was buried at St John's Anglican Church in Canberra.