Local elections were held in Northern Ireland on 18 May 2023. The elections were delayed by two weeks to avoid overlapping with the coronation of King Charles III. Following the elections, Sinn Féin became the largest party in local government for the first time. It also marked the first time that nationalist parties had garnered a greater share of the vote than unionist parties.
 Northern Ireland uses the single transferable vote (STV) electoral system to elect members of local councils and members of the Northern Ireland Assembly. Voters rank candidates in order of preference by marking 1, 2, 3, etc. to the names of candidates on a ballot paper and can rank as many or as few candidates as they like or just vote for one candidate.
 These were the second Northern Irish elections and the first local election at which people were able to register to vote online.
 In previous local elections, a unionist party had always won the most seats. In the 2019 Northern Ireland local elections, the Democratic Unionist Party (DUP) had come first.
 At the 2022 Northern Ireland Assembly election, Sinn Féin became the biggest political party in the Assembly for the first time. It was also the first time that the DUP didn't assume the position of First Minister-designate since 2007. Due to the terms outlined in the Good Friday Agreement, the largest nationalist party and the largest unionist party must be in government together. The Executive, Northern Ireland's government, is not currently sitting as the DUP has refused to enter government due to the Northern Ireland Protocol, an agreement between the European Union (EU) and the United Kingdom (UK) that governs the unique customs and immigration issues at the border between Republic of Ireland and Northern Ireland. This move has proved controversial, with the Vice President of Sinn Féin and First Minister-designate, Michelle O'Neill saying that it's "totally unacceptable" for the DUP to refuse to enter the Executive amid a crisis. The Social Democratic and Labour Party (SDLP) has accused the DUP of treating voters with contempt and "making our electoral process look like a bad joke" and Naomi Long, leader of the Alliance Party, said DUP Assembly Members should not be allowed to claim their salary while they prevented the Assembly from functioning.
 The full list of candidates was revealed on 18 May 2023.
 In the table above, U signifies unionist, N nationalist and O other.
 The counting of votes began on 19 May 2023 and finished on 21 May 2023. Preliminary results showed Sinn Féin overtaking the DUP as the largest party in local government. In one DEA, Waterside in Derry and Strabane, the result was incorrectly declared prematurely and the counting of votes was not completed; the counting of votes there resumed on 9 August 2023.
 As is common in Northern Ireland under the single transferable vote electoral system, ten of the eleven councils were under no overall control. The exception was Fermanagh and Omagh District Council where Sinn Féin won 21 seats to take a majority of two, becoming the only single party with control of a district council.
 Results were published by BBC News.
 
 According journalist Jonathan McCambridge, Sinn Féin's victory was largely helped by them pointing the finger at the DUP's reluctance to get Stormont back and running, even though the DUP's vote share was largely unchanged.
 An editorial in the Orange Standard, the official newspaper of the loyalist Orange Order, said the results of the election, and low voter turnout in several unionist areas, had presented serious challenges for the DUP, the UUP and other unionist parties. "The need to significantly reduce apathy amongst the unionist voter base was one of the issues that came to the fore. In some areas with a unionist majority the turnout of eligible voters was as low as 40%," it said. "A significant piece of work must be carried out to enhance unionist engagement with the political process – and in particular when it comes to elections. As a unionist community we must stand up and be counted when it really matters."