In 2011, there was a massive attack by a lone gunman in Oslo and on an island to the Northwest of the city about 2 hours away. The 2011 Norway attacks were two sequential lone wolf terrorist attacks by Anders Behring Breivik against the government, the civilian population, and a Workers' Youth League (AUF)-run summer camp in Norway on 22 July 2011. The attacks claimed a total of 77 lives.

The first attack was a car bomb explosion in Oslo within Regjeringskvartalet, the executive government quarter of Norway, at 15:25:22 (CEST). The bomb was made from a mixture of fertilizer and fuel oil and placed in the back of a van. The van was placed in front of the office block housing the office of Prime Minister Jens Stoltenberg and other government buildings. The explosion killed eight people and injured at least 209 people, twelve of them seriously.

The second attack occurred less than two hours later at a summer camp on the island of Utøya in Tyrifjorden, Buskerud. The camp was organized by the AUF, the youth division of the ruling Norwegian Labor Party (AP). A gunman dressed in a homemade police uniform and showing false identification gained access to the island and subsequently opened fire at the participants, killing 69 of them, and injuring at least 110 people, 55 of them seriously; the 69th victim died in a hospital two days after the massacre. Among the dead were personal friends of Prime Minister Jens Stoltenberg and the stepbrother of Norway's crown princess Mette-Marit.

It was the deadliest attack in Norway since World War II, and a survey found that one in four Norwegians knew "someone affected by the attacks". On 13 August 2012, Norway's prime minister received the Gjørv Report which concluded that Norway's police could have prevented the bombing of central Oslo and caught the gunman faster at Utøya, and that more security and emergency measures to prevent further attacks and "mitigate adverse effects" should have been implemented on 22 July.