He first entered Parliament at the 1685 English general election when returned unopposed as MP for Ripon on his father's interest.
In 1688, he returned negative answers on the repeal of the Test Act and the Penal Laws and was dismissed from the Commission of the Peace.
He conducted a considerable amount of routine parliamentary business, and was noted as one of the lawyers particularly interested in introducing legislative change.
He refused to take the Oath of Association, introduced by the House of Commons after the failure of the Jacobite assassination plot 1696, apparently, because he objected to the reference to the life of King William III having been saved by divine providence, which in his view raised the question of whether he was King by Divine Right.
He was involved in preparing a bill to prevent bribery at elections on 17 January 1702) and as a Tory, he supported the motion of 26 February 1702 which vindicated the Commons’ proceedings in the impeachments of William III's ministers.
[6] In the debates following the celebrated judgment in Ashby v White, Dolben argued strongly that the House of Commons had exclusive jurisdiction over all disputed Parliamentary elections.
[3] When Dolben became a judge of the Court of Common Pleas (Ireland) in 1701, he joined the King's Inn, the professional body which governed the Irish Bar[7] He retained the post on the accession of Queen Anne in 1702.
He remained a member of the English House of Commons, and divided his time between England and Ireland, somewhat to the neglect of his judicial duties.
[3] For many years he was greatly troubled by the profligacy of his brother John, an inveterate gambler who ran through all his own money and then his wife's.
In 1691 Gilbert wrote that John's wife and children were living on the charity of friends, something he described as shameful for the family, and a reproach to his father's memory, as critics accused the Archbishop of having been a neglectful parent.
He was a man of scholarly tastes: John Dryden acknowledged the help Dolben had given him in preparing his translations of Virgil.