The Massereene Barracks shooting took place at Massereene Barracks in Antrim, Northern Ireland. On 7 March 2009, two off-duty British soldiers of 38 Engineer Regiment were shot dead outside the barracks. Two other soldiers and two civilian delivery men were also shot and wounded during the attack. A dissident Irish republican paramilitary group, the Real IRA, claimed responsibility.

The shootings were the first British military fatalities in Northern Ireland since 1997. Two days later, the Continuity IRA shot dead Stephen Carroll a Police Service of Northern Ireland (PSNI) officer; the first Northern Ireland police officer to be killed by paramilitaries since 1998.

The Real Irish Republican Army, or Real IRA (RIRA), is a dissident Irish republican paramilitary group that aims to bring about a United Ireland. It formed in 1997 following a split in the Provisional IRA by dissident members, who rejected the IRA's ceasefire that year. Like the Provisional IRA before it, the Real IRA sees itself as the only rightful successor to the original Irish Republican Army and styles itself as simply "the Irish Republican Army" in English or Óglaigh na hÉireann in Irish. It is an illegal organisation in the Republic of Ireland and designated as a proscribed terrorist organisation in the United Kingdom and the United States.

Since its formation, the Real IRA has waged a campaign in Northern Ireland against the Police Service of Northern Ireland (PSNI)—formerly the Royal Ulster Constabulary (RUC)—and the British Army. It is the largest and most active of the "dissident republican" paramilitary groups operating against the British security forces. It has targeted the security forces in firearm attacks and bombings, and with grenades, mortars and rockets. The organisation has also been responsible for bombings in Northern Ireland and England with the goal of causing economic harm and disruption. The most notable of these was the 1998 Omagh bombing, which killed 29 people. After that bombing the Real IRA went on ceasefire, but resumed operations again in 2000. In March 2009 it claimed responsibility for an attack on Massereene Barracks which killed two British soldiers, the first to be killed in Northern Ireland since 1997. The Real IRA has also been involved in attacks on drug dealers.

In July 2012, it was reported that Republican Action Against Drugs (RAAD) and other small republican militant groups were merging with the Real IRA. This new entity was named the New IRA (NIRA) by the media but members continue to identify themselves as simply "the Irish Republican Army". Small pockets of the Real IRA that did not merge with the New IRA continue to have a presence in the Republic of Ireland, particularly in Cork and to a lesser extent in Dublin.