Dungannon was a parliamentary constituency of the House of Commons of the Parliament of the United Kingdom 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. This act split County Tyrone into four single-member constituencies: East Tyrone, Mid Tyrone, North Tyrone and South Tyrone. It took effect at the 1885 United Kingdom general election.
This constituency was the parliamentary borough of Dungannon in County Tyrone.
Knox resigned, causing a by-election.
Knox resigned, causing a by-election.
Knox resigned due to ill health by accepting the office of Steward of the Chiltern Hundreds, causing a by-election.
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.
On petition, Dickson was unseated and a by-election was called.