Until recent years, Terrorism in Sweden was not seen as serious threat to the security of the state. The terrorism-related event in modern Swedish history which received the most attention was the West German embassy siege in 1975, which was carried out by the Red Army Faction. In 1976, the same group also planned Operation Leo which was to involve the kidnapping of Anna-Greta Leijon, but which was never set in action.
Then, the highest level violent action in Sweden to date happened in 1986, when Swedish Prime Minister Olof Palme was killed in an action of dubious motivations. Several different terrorist leads were considered, but none has been proved conclusive, and the police main lead was a lone madman.
The neo-nazi activist group Swedish Resistance Movement (SRM) was formed in 1997 and merged into the Nordic Resistance Movement (NRM) in 2016. The group has been behind several violent actions since a bomb and the murder of the journalist Björn Söderberg in 1999. In 2017, NRM members were arrested for involvement in two bombings and a bombing attempt in Gothenborg, near two refugee accommodations and a syndicalist organization.
Over the last decades the issue of certain terrorist groups, such as Kurdistan Workers' Party (PKK), using Sweden as a free haven has received attention. In the 2000s, the issue of terrorism financing and recruiting for terrorist groups, including Islamic groups, have also been on the security agenda. Criminal acts from domestic political extremist groups, both on the right and on the left, have also become an increasing phenomenon.
The Swedish government agency tasked with keeping watch over terrorism-related threats is the Swedish Security Service.
Human Rights Watch criticized the Swedish government after police in Stockholm arrested Uzbek political opposition leader Muhammad Salih on May 18, 2006. Holly Cartner, HRW Executive Director for Europe and Central Asia, said the "fact that President Karimov can travel freely to Europe while Mohammad Solih remains subject to an Interpol warrant is plainly absurd."
The perpetrator of the 2009–10 Malmö shootings targeted minorities. Serial killer John Ausonius also targeted minorities.
The 2010 Stockholm bombings occurred on 11 December 2010 when two bombs exploded in central Stockholm, Sweden, killing the bomber and injuring two people. Swedish Minister for Foreign Affairs Carl Bildt and the Swedish Security Service (SÄPO) described the bombings as acts of terrorism. Taimour Abdulwahab al-Abdaly, an Iraqi-born Swedish citizen, is suspected of carrying out the bombing. The Norwegian Broadcasting Corporation described the event as the first suicide attack linked to Islamic terrorism in the Nordic countries.
The 2011 Gothenburg terrorism plot was alleged to target art festival and Swedish artist Lars Vilks and thwarted by police. Four people were arrested, three charged, and all three suspects were acquitted.
The 2015 Trollhättan school attack was carried out by 21-year-old Anton Lundin Pettersson, who killed two teachers and one student. The police described it as a hate crime with racist motives.
In the 2016 Sweden terrorism plot Aydin Sevigin was convicted to carry out an ISIS-inspired suicide bombing on Swedish soil using a homemade pressure-cooker bomb.