Dungannon was a United Kingdom Parliament constituency, in Ireland, returning one MP.
It was an original constituency represented in Parliament when the Union of Great Britain and Ireland took effect on 1 January 1801 and was abolished by the Redistribution of Seats Act 1885.
Knox resigned due to ill health by accepting the office of Steward of the Chiltern Hundreds, causing a by-election.
[5] Knox resigned again by accepting the office of Steward of the Chiltern Hundreds, causing a by-election.
Knox was appointed a Groom in Waiting to Queen Victoria, causing a by-election.