Since the constituency's creation in 1997 it has consisted of the territory of the former Districts of Omagh and Strabane. There were major local government boundary changes in 2015, but the constituency boundaries remained unchanged. The seat was created in a boundary review conducted in 1995 and was predominantly made out of the western half of the old Mid Ulster constituency – indeed it contains more of the old Mid Ulster than the current seat of that name. It also contains parts of the old Foyle constituency. Although the Boundary Commission altered several Northern Ireland constituencies for the 2010 general election, West Tyrone was left unchanged.
History
For the history of the equivalent seat prior to 1997, see Mid Ulster. The seat is overwhelmingly nationalist, as evidenced by the election results in which nationalist parties have always won over 50% of the vote since the seat was created. However, the nationalist vote has traditionally been split between the Social Democratic and Labour Party and Sinn Féin, whilst the unionist parties have been more willing to make pacts to increase their chances of victory. When the seat was created it was nominally held by the Democratic Unionist Party, based on mapping the 1992 general election results onto the new boundaries, but this was because the Ulster Unionist Party had not contested the equivalent area. In the 1996 Forum elections the UUP outpolled the DUP and it was agreed that the DUP would not contest the seat. As a result William Thompson of the UUP won in 1997 with a narrow majority over the SDLP, with Sinn Féin coming third on a large vote. In the 2001 general election the SDLP and Sinn Féin both targeted the constituency heavily, in the hope that a shift in the vote from one nationalist party to the other would enable them to outpoll the Ulster Unionists. In the event Sinn Féin's Pat Doherty won. In 1998 both Sinn Féin and the SDLP won two seats in the Northern Ireland Assembly, with the UUP and DUP winning one each. However, there was much speculation that an increase in Sinn Féin's vote at the SDLP's expense would result in Sinn Féin taking a seat from its nationalist rival at the next assembly election. However, the election was complicated by the intervention of the independent candidate Dr. Kieran Deeny, campaigning on the sole issue of the retention of the hospital in Omagh. In a result that shocked commentators he took one of the SDLP's assembly seats. Deeny stood again in the 2005 general election and asked most parties to withdraw to support him. Many local activists and voters appeared to agree with this, with some making their support public, but in the end the UUP, DUP and SDLP all fielded candidates. Doherty held the seat for Sinn Féin, but with Deeny polling strongly in second place.
