John was the second son of James Rolt, a merchant of Calcutta, and Anne née Braine. He was born at Calcutta and brought to England by his mother about 1810. He was educated at dissenting private schools at Chipping Norton and Islington. His father died in 1813, and his mother in the following year. Around Christmas 1818, Rolt was apprenticed to a London firm of woollendrapers. Though his hours were long, he managed, by early rising and reading as he walked, to educate himself despite the disadvantages of his early life. On the expiration of his indentures in 1822–1823, he found employment in a Manchester warehouse in Newgate Street, which he exchanged in 1827 for a clerkship in a proctor's office at Doctors' Commons. His next step was to obtain two secretaryships. One to a school for orphans, the other to the Mill Hill School.
Meanwhile, he pursued his studies, and in 1833 entered the Inner Temple, where he was called to the Bar on 9 June 1837. Confining himself to the Court of Chancery, he rapidly acquired an extensive practice, in particular following his opinion for a large London firm in Stubbs v Lister, which also led to a friendship with Edwin Wilkins Field. He took silk in Trinity vacation 1846. After some unsuccessful attempts to enter parliament, he was returned for the Conservatives for West Gloucestershire on 31 March 1857, and for ten years continued to represent the same constituency. In 1862 he carried through the House of Commons the measure commonly known as Rolt's Act, by which an important step was taken towards the fusion of law and equity. In 1866 he succeeded Sir Hugh Cairns as Attorney General on 29 October, and was knighted on 10 November.
On 18 July 1867 he succeeded Sir George James Turner as Lord Justice of Appeal, and on 3 August was sworn to the Privy Council. Incipient paralysis, due to long-continued overwork, compelled his resignation in February 1868, and on 6 June 1871 he died at his estate, Ozleworth Park, Wotton-under-Edge, Gloucestershire. He was buried on 12 June in Ozleworth churchyard.
It has been said that In parliament Rolt made no great figure, but he voted steadily with his party, and did the drudgery connected with the carriage of the Reform Bill of 1867. Rolt was neither a profound lawyer nor a great advocate; but he was thoroughly versed in chancery practice, had sound judgment, and quickness of apprehension.
|Parliament of the United Kingdom|
Robert Blagden Hale
| Member of Parliament for West Gloucestershire
With: Robert Kingscote
Edward Arthur Somerset
Sir Hugh Cairns
| Attorney General for England and Wales
Sir John Burgess Karslake