2024–present: The District of Armagh, Banbridge and Craigavon, the District of Fermanagh and Omagh wards of Blackwatertown, Ballinamallard, Belcoo & Garrison, Belleek & Boa, Boho, Cleenish & Letterbreen, Brookeborough, Castlecoole, Derrygonnelly, Derrylin, Donagh, Ederney & Kesh, Erne, Florence Court & Kinawley, Irvinestown, Lisbellaw, Lisnarrick, Lisnaskea, Maguiresbridge, Newtownbutler, Portora, Rosslea, Rossorry, and Tempo, and the District of Mid Ulster wards of Augher & Clogher, Aughnacloy, Ballygawley, Ballysaggart, Caledon, Castlecaulfield, Fivemiletown, Killymeal, Moy, Moygashel, and Mullaghmore.

Perhaps because of this balance between the communities, Fermanagh and South Tyrone has repeatedly had the highest turn-out (and the smallest winning margin) of any constituency in Northern Ireland.

In 1955 the constituency was won by Philip Clarke of Sinn Féin, but he was unseated on petition on the basis that his criminal conviction (for Irish Republican Army activity) made him ineligible.

In 1970 the seat was won by Frank McManus, standing on the "Unity" ticket that sought to unite nationalist voters behind a single candidate.

In the October 1974 general election a nationalist pact was agreed and Frank Maguire won, standing as an Independent Republican.

Morrow then withdrew in favour of Jim Dixon, a survivor of the Enniskillen bombing who stood as an Independent Unionist opposed to the Agreement.

Although Elliott was running for the UUP, he was also being actively supported by the DUP, the Traditional Unionist Voice and the UK Independence Party.

[5] Just as in the February 1974 and 1983 elections, faced with a single Unionist candidate, the SDLP refused to discuss a nationalist pact with Sinn Féin.

In the 2019 election she was re-elected with a majority of just 57 votes (the narrowest result in the UK), despite the DUP withdrawing and the SDLP standing a candidate.

This made the 2019 election the second time in under ten years that Fermanagh and South Tyrone has been the seat with the smallest winning majority in the UK.

In the General Election 2024, Royal College of Nursing chief Pat Cullen announced that she would contest the seat representing Sinn Féin.

Cullen won the seat, with a majority of 4,486 votes despite being against single unionist candidate, Diana Armstrong of the UUP.

Cullen increased Sinn Féin's vote share in Fermanagh South Tyrone by 6.7%, securing the largest Nationalist majority since the 2005 general election.