2011 Northern Ireland Assembly election

The 2011 Northern Ireland Assembly election took place on Thursday, 5 May, following the dissolution of the Northern Ireland Assembly at midnight on 24 March 2011. It was the fourth election to take place since the devolved assembly was established in 1998.

It was held on the same day as elections for Northern Ireland's 26 local councils, the Scottish Parliament and Welsh Assembly elections, a number of local elections in England and the United Kingdom Alternative Vote referendum. As in the past, the 2011 election to the Assembly was conducted using the single transferable vote (STV) system of proportional representation. The 108 seats were contested in 18 constituencies by 218 candidates, including 15 independents and the nominees of 14 separate political parties.

1,210,009 individuals were registered to vote in the 2011 Assembly election (representing an increase of 9.2% compared to the 2007 Assembly election). Turnout in the 2011 Assembly election was 55.7%, a decline of almost seven percentage points from the previous Assembly election and down over 14 percentage points from the first election to the Assembly in 1998.

As in the 2007 election, the Democratic Unionist Party (DUP) and Sinn Féin (SF) remained the two largest parties in the Assembly, with the DUP winning 38 and Sinn Féin winning 29 of the Assembly's 108 seats. The Ulster Unionist Party (UUP) won 16 seats, the Social Democratic and Labour Party (SDLP) 14 and the Alliance 8, while one seat each was won by the Green Party, Traditional Unionist Voice (TUV) and an independent candidate.

Following the results of the election, Peter Robinson of the DUP and Martin McGuinness of Sinn Féin were nominated and subsequently re-elected as First Minister and deputy First Minister on 12 May 2011. The sole change to the Northern Ireland Executive was that the UUP lost a ministerial post to the Alliance.

The election was the first since the devolution of policing and justice powers to the assembly. In contrast to previous elections, it was relatively uncontroversial. The turnout was one of the lowest ever in a Northern Ireland election. Sinn Féin and the Democratic Unionist Party both continued to make gains, although the DUP vote share was slightly down. The election was a disaster for the Ulster Unionist Party, which came behind the Social Democratic and Labour Party in terms of first preference vote, although the UUP won more seats. The Ulster Unionist vote collapsed in Belfast, where it was eclipsed by the Alliance Party's, and in a number of other constituencies considered safe such as North Down. The election was also poor for the SDLP, which lost two seats.

The Alliance Party performed well, gaining a second seat in East Belfast (which a former Progressive Unionist Party member lost and the PUP failed to regain), while increasing the Alliance vote share significantly. Traditional Unionist Voice secured a single seat in North Antrim; its vote share was down from the May 2010 elections to the UK Parliament. Despite their first preference vote halving, the Green Party held their sole seat in North Down while the People before Profit Alliance narrowly failed to take the final seat in the Foyle constituency. The only member elected as an independent in 2007 (in West Tyrone) retired, leaving a single independent in the new Assembly (after three independents first elected on other tickets had retired or lost re-election), compared to five at the end of the previous one.

As in the previous Assembly, the DUP's voting strength was reduced by one with the re-election on 12 May of Willie Hay (DUP, Foyle) to the non-partisan office of Speaker.