The Real Irish Republican Army carried out a rocket-launcher attack on the MI6 headquarters in London, with no casualties and minimal damage recorded.

The Real Irish Republican Army, or Real IRA (RIRA), was a dissident Irish republican paramilitary group that aimed to bring about a United Ireland. It was 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 saw itself as the only rightful successor to the original Irish Republican Army and styled itself as simply "the Irish Republican Army" in English or Óglaigh na hÉireann in Irish. It was an illegal organisation in the Republic of Ireland and designated a proscribed terrorist organisation in the United Kingdom and the United States.

On Wednesday 20 September 2000, the Real Irish Republican Army (RIRA) carried out an attack on MI6's SIS Building headquarters in Vauxhall, Lambeth, London. A Russian-built RPG-22 anti-tank rocket, fired 300 metres away from MI6 headquarters, struck the building on the south side of the eighth floor, causing superficial damage. No fatalities or injuries were recorded.

The SIS Building, also called the MI6 Building, at Vauxhall Cross houses the headquarters of the Secret Intelligence Service (SIS), also known as Military Intelligence, Section 6 (MI6), the United Kingdom's foreign intelligence agency. It is located at 85 Albert Embankment in Vauxhall, London, on the bank of the River Thames beside Vauxhall Bridge. The building has been the headquarters of the SIS since 1994.