A by-election is due to be held in the Dáil constituency of Dublin Central in Ireland in 2026, to fill the vacancy left by the resignation of Paschal Donohoe on 21 November 2025. Under the Electoral (Amendment) Act 2011, the writ for the by-election must be issued within six months of the vacancy. In February 2026, Taoiseach Micheál Martin said the by-election would be held in May, together with the 2026 Galway West by-election.
The Dáil constituency of Dublin Central elects four TDs. Dublin Central is regarded as one of the most social and ethnically diverse constituencies in Ireland. In 2020, the constituency's population was 65.7% Irish, versus 87% for the country as a whole. The constituency consists of largely traditional working class areas such as East Wall, North Strand, Summerhill, Ballybough, Sheriff Street and Cabra with more suburban middle class Stoneybatter, Phibsborough, Glasnevin and Lower Drumcondra on the northern fringes of the constituency. It contains O'Connell Street, the Four Courts and the IFSC. Dublin Central was the location of the 2023 Dublin riot, and anti-immigration candidates have a presence here. At the 2024 general election, Dublin Central elected one Sinn Féin, one Social Democrat, one Fine Gael and one Labour TD.
On 19 November 2025, independent Dublin City councillor Malachy Steenson confirmed his intention to stand. Alleged crime boss Gerry Hutch confirmed his intention to stand on 23 November 2025. Musician and activist Eoghan àCeannabháin was announced as the candidate for People Before Profit on 10 December 2025. On 16 December 2025, councillor Daniel Ennis was selected as the Social Democrats candidate.
Aontú announced Ian Noel Smyth as their candidate on 15 January 2026. On 4 February 2026, the Green Party announced that the party's Cathaoirleach, Dublin City Councillor Janet Horner would be the party's candidate in the by-election. On 25 February, Sinn Féin councillor Janice Boylan, who was Mary Lou McDonald's running mate in Dublin Central at the 2024 general election, was chosen as the party's candidate at a selection convention. In February 2026, Colm Flood, a former People Before Profit member announced that he would run as an independent candidate.
On 2 March 2026, Ruth O'Dea was selected as the Labour Party candidate. On 23 March 2026, councillor Ray McAdam, the current Lord Mayor of Dublin was announced as the Fine Gael candidate. On 30 March 2026, councillor John Stephens was selected as the Fianna Fáil candidate.
The Sunday Times reported on 31 January 2026 that Sinn Féin was likely to ratify Gillian Sherratt, who led a high-profile campaign against Children's Health Ireland after her son Harvey Morrison died while awaiting surgery for scoliosis, however she was beaten in the selection process by councillor Janice Boylan.
Fianna Fáil Senator Mary Fitzpatrick, who has contested five general elections in Dublin Central, confirmed that she would not seek the party's nomination for the by-election.