The Continuity Irish Republican Army (Continuity IRA or CIRA), styling itself as the Irish Republican Army (Irish: Óglaigh na hÉireann), is an Irish republican paramilitary group that aims to bring about a united Ireland. It claims to be a direct continuation of the original Irish Republican Army and the national army of the Irish Republic that was proclaimed in 1916. It emerged from a split in the Provisional IRA in 1986 but did not become active until the Provisional IRA ceasefire of 1994. It is an illegal organisation in the Republic of Ireland and is designated a terrorist organisation in the United Kingdom, New Zealand and the United States. It has links with the political party Republican Sinn Féin (RSF).

Since 1994, the CIRA has waged a campaign in Northern Ireland against the British Army and the Police Service of Northern Ireland (PSNI), formerly the Royal Ulster Constabulary. This is part of a wider campaign against the British security forces by dissident republican paramilitaries. It has targeted the security forces in gun attacks and bombings, as well as with grenades, mortars and rockets. The CIRA has also carried out bombings with the goal of causing economic harm and/or disruption, as well as many punishment attacks on alleged criminals.

To date, it has been responsible for the death of one PSNI officer. The CIRA was smaller and less active than the now-defunct Real IRA, and there have been a number of splits within the organisation since the mid-2000s.

The Continuity IRA has its origins in a split in the Provisional IRA. In September 1986, the Provisional IRA held a General Army Convention (GAC), the organisation's supreme decision-making body. It was the first GAC in 16 years. The meeting, which like all such meetings was secret, was convened to discuss among other resolutions, the articles of the Provisional IRA constitution which dealt with abstentionism, specifically its opposition to the taking of seats in Dáil Éireann (the parliament of the Republic of Ireland). The GAC passed motions (by the necessary two-thirds majority) allowing members of the Provisional IRA to discuss and debate the taking of parliamentary seats, and the removal of the ban on members of the organisation from supporting any successful republican candidate who took their seat in Dáil Éireann.

The Provisional IRA convention delegates opposed to the change in the constitution claimed that the convention was gerrymandered "by the creation of new IRA organisational structures for the convention, including the combinations of Sligo-Roscommon-Longford and Wicklow-Wexford-Waterford." The only IRA body that supported this viewpoint was the outgoing IRA Executive. Those members of the outgoing Executive who opposed the change comprised a quorum. They met, dismissed those in favour of the change, and set up a new Executive. They contacted Tom Maguire, who was a commander in the old IRA and had supported the Provisionals against the Official IRA (see Irish republican legitimatism), and asked him for support. Maguire had also been contacted by supporters of Gerry Adams, then president of Sinn Féin, and a supporter of the change in the Provisional IRA constitution.

Maguire rejected Adams' supporters, supported the IRA Executive members opposed to the change, and named the new organisers the Continuity Army Council. In a 1986 statement, he rejected "the legitimacy of an Army Council styling itself the Council of the Irish Republican Army which lends support to any person or organisation styling itself as Sinn Féin and prepared to enter the partition parliament of Leinster House." In 1987, Maguire described the "Continuity Executive" as the "lawful Executive of the Irish Republican Army."

Initially, the Continuity IRA did not reveal its existence, either in the form of press statements or paramilitary activity. Although the Garda Síochána had suspicions that the organisation existed, they were unsure of its name, labelling it the "Irish National Republican Army". On 21 January 1994, on the 75th anniversary of the First Dáil Éireann, a group of men in paramilitary dress offered a "final salute" to Tom Maguire by firing over his grave. A public statement headed "Irish Republican Publicity Bureau" signed "B Ó Ruairc, Rúnaí [Secretary]" identifying the firing party as "Volunteers of Óglaigh na hÉireann-the Irish Republican Army", and two accompanying photos were published in Saoirse Irish Freedom. Garda Special Branch detectives raided the headquarters of Republican Sinn Féin at Arran Quay, Dublin, two days after the graveside volley, seizing files and questioning staff. In February 1994 it was reported that in previous months Gardaí had found arms dumps along the Cooley Peninsula in County Louth that did not belong to the Provisional IRA, and forensics tests determined had been used for firing practice recently.

It was only after the Provisional IRA declared a ceasefire in 1994 that the Continuity IRA became active, announcing its intention to continue the campaign against British rule. The CIRA continues to oppose the Good Friday Agreement and, unlike the Provisional IRA (and the Real IRA in 1998), the CIRA has not announced a ceasefire or agreed to participate in weapons decommissioning—nor is there any evidence that it will. In the 18th Independent Monitoring Commission's report, the RIRA, the CIRA and the Irish National Liberation Army (INLA) were deemed a potential future threat. The CIRA was labelled "active, dangerous and committed and... capable of a greater level of violent and other crime". Like the RIRA and RIRA splinter group Óglaigh na hÉireann, it too sought funds for expansion. It is also known to have worked with the INLA.^{[citation needed]}