A national unity government, government of national unity (GNU), or national union government is a broad coalition government consisting of all parties (or all major parties) in the legislature, usually formed during a time of war or other national emergency. A unity government according to the principles of consensus democracy lacks opposition, or opposition parties are too small and negligible.

Following the disputed 2014 presidential elections, a National Unity Government (NUG) between both run-off candidates was formed with Ashraf Ghani as President of Afghanistan and Abdullah Abdullah in the new office of Chief Executive of Afghanistan. This power-sharing agreement broke apart after the 2019 Afghan presidential election, after which Ghani abolished the office of Chief Executive while Abdullah again refused to recognize Ghani's presidency and demanded the formation of a new government in northern Afghanistan. Both politicians lost power after the Taliban overthrew the Afghan government in 2021.

During World War I, the Conservative government of Sir Robert Borden invited the Liberal opposition to join the government as a means of dealing with the Conscription crisis of 1917. The Liberals, led by Sir Wilfrid Laurier refused; however, Borden was able to convince many individual Liberals to join what was called a Union Government, which defeated the Laurier Liberals in the fall 1917 election.

During World War II, the opposition Conservative Party ran under the name National Government in the 1940 election as a means of promoting their platform of creating a wartime national government coalition (evocative of the previous war's Union government). The party was not successful in the election, which re-elected the Liberal government of William Lyon Mackenzie King, whose party continued to rule alone for the duration of World War II.

The Dominion of Newfoundland (not to be part of Canada for another three decades) had a National Government during World War I led by Edward Patrick Morris.

In modern Chinese history, the Republic of China twice saw United Fronts forms to provide national unity in a time of civil conflict. The First United Front (1923–1927) saw the Nationalists (KMT) and Communists (CCP) unite to end warlordism within the country, however since neither party was the centrally recognised Government of China at the time the First United Front cannot be viewed as a true example of a national unity government.

Following the advent of the Second Sino-Japanese War, the KMT, the now solely recognised central party of the country, once again opted to form the Second United Front with the CCP – the two parties at this point had been engaged in an open civil war since the collapse of the First United Front. This new front acted as a national unity government for the extent of the war and represented the solely recognised government for China at the time, though the overall level of cooperation between the two parties – past the cessation of hostility – was mostly nominal.

Croatia formed a national unity government in 1991 under prime minister Franjo Gregurić in response to the outbreak of the Croatian War of Independence. Even though the cabinet included ministers from minority parties, all heads of ministries were either from the majority Croatian Democratic Union or soon defected to it.