The Quisling regime, or Quisling government are common names used to refer to the collaboration government led by Vidkun Quisling in German-occupied Norway during the Second World War. The official name of the regime from 1 February 1942 until its dissolution in May 1945 was the National Government (Norwegian: Den nasjonale regjering). Actual executive power was retained by the Reichskommissariat Norwegen, headed by Josef Terboven.

Vidkun Quisling, Fører of the Nasjonal Samling party, first tried to carry out a coup against the Norwegian government on 9 April 1940, the day of the German invasion of Norway. At 7:32 p.m., Quisling visited the studios of the Norwegian Broadcasting Corporation and made a radio broadcast proclaiming himself Prime Minister and ordering all resistance to halt immediately. He announced that he and Nasjonal Samling were taking power due to Nygaardsvold's Cabinet having "raised armed resistance and promptly fled". He further declared that in the present situation it was "the duty and the right of the movement of Nasjonal Samling to take over governmental power". Quisling claimed that the Nygaardsvold Cabinet had given up power, even though that it had only moved to Elverum, some 140 kilometres (87 mi) from Oslo, and was carrying out negotiations with the Germans.

The next day, German ambassador Curt Bräuer travelled to Elverum and demanded King Haakon VII return to Oslo and formally appoint Quisling as prime minister. Haakon stalled for time, telling the ambassador that Norwegian kings could not make political decisions on their own authority. At a Cabinet meeting later that night, Haakon said that he could not in good conscience appoint Quisling as prime minister because he knew neither the people nor the Storting had confidence in him. Haakon further stated that he would abdicate rather than appoint a government headed by Quisling. By this time, news of Quisling's attempted coup had reached Elverum. Negotiations promptly collapsed, and the government unanimously advised Haakon not to appoint Quisling as prime minister.^{[citation needed]}

Quisling tried to have the Nygaardsvold Cabinet arrested, but the officer he instructed to carry out the arrest ignored the warrant. Attempts at gaining control over the police force in Oslo by issuing orders to Kristian Welhaven, the chief of police, also failed. The coup failed after six days, despite German support for the first three days, and Quisling had to step aside in the occupied parts of Norway in favour of the Administrative Council (Administrasjonsrådet). The Administrative Council was formed on 15 April by members of the Supreme Court and supported by Norwegian business leaders as well as Bräuer as an alternative to Quisling's Nasjonal Samling in the occupied areas.

On 25 September 1940, German Reichskommissar Josef Terboven, who on 24 April 1940 had replaced Curt Bräuer as the top civilian commander in Norway, proclaimed the deposition of King Haakon VII and the Nygaardsvold Cabinet, banning all political parties other than Nasjonal Samling. Terboven then appointed a group of 11 kommissariske statsråder (English: provisional councillors of state) from Nasjonal Samling to help him in governing Norway. Although the provisional councillors of state did not form a government, the intention of the Germans was to use them to prepare the way for a Nasjonal Samling take-over of power in the future. Vidkun Quisling was made the political head of the councillors and all members of Nasjonal Samling had to swear a personal oath of allegiance to him. Most of the councillors worked diligently at introducing Nasjonal Samling ideals and politics. Amongst the schemes introduced during the council period was the introduction of labour duty, reforms of the labour market, the penal code and the system of justice, a reorganization of the police and the introduction of national socialist ideals in the Norwegian culture scene. The provisional councillors of state were intended as a temporary system while Nasjonal Samling built up its organization in preparation for assuming full governmental powers. On 25 September 1941, the one-year anniversary of the councillors, Terboven gave them the title of "ministers".

With the establishment of Quisling's national government, Quisling, as minister-president, temporarily assumed the authority of both the King and the Parliament.

In 1942, after two years of direct civilian administration by the Germans (which continued de facto until 1945), he was finally put in charge of a collaborationist government, which was officially proclaimed on 1 February 1942. The official name of the government was "Den nasjonale regjering" (English: the National Government). The original intention of the Germans had been to hand over the sovereignty of Norway to the new government, but by mid-January 1942 Hitler decided to retain the civilian Reichskommissariat Norwegen under Terboven. The Quisling government was instead given the role of an occupying authority with wide-ranging authorisations. Quisling himself viewed the creation of his government as a "decisive step on the road towards the complete independence of Norway". Although having only temporarily assumed the King's authority, Quisling still made efforts to distance his regime from the exiled monarchy. After Quisling moved into the Royal Palace he took back into use the official seal of Norway, changing the wording from "Haakon VII Norges konge" to "Norges rikes segl" (in English, from "Haakon VII King of Norway" to "The Seal of the Norwegian Realm"). After establishing national government Quisling claimed to hold "the authority that according to the Constitution belonged to the King and Parliament".

Other important ministers of the collaborationist government were Jonas Lie (also head of the Norwegian wing of the SS from 1941) as Minister of the Police, Gulbrand Lunde as Minister of Culture and Enlightenment, as well as the opera singer Albert Viljam Hagelin, who was Minister of the Interior.