Nineteen Eighty-Four (also stylised as 1984) is a dystopian social science fiction novel and cautionary tale written by English writer George Orwell. It was published on 8 June 1949 by Secker & Warburg as Orwell's ninth and final book completed in his lifetime. Thematically, it centres on the consequences of totalitarianism, mass surveillance and repressive regimentation of people and behaviours within society. Orwell, a democratic socialist, modelled the totalitarian government in the novel after Stalinist Russia and Nazi Germany. More broadly, the novel examines the role of truth and facts within politics and the ways in which they are manipulated.

The story takes place in an imagined future, the year 1984, when much of the world has fallen victim to perpetual war, omnipresent government surveillance, historical negationism, and propaganda. Great Britain, known as Airstrip One, has become a province of the totalitarian superstate Oceania, ruled by the Party, who employ the Thought Police to persecute individuality and independent thinking. Big Brother, the dictatorial leader of Oceania, enjoys an intense cult of personality, manufactured by the party's excessive brainwashing techniques. The protagonist, Winston Smith, is a diligent and skillful rank-and-file worker at the Ministry of Truth and Outer Party member who secretly hates the Party and dreams of rebellion. He expresses his dissent by writing in a diary and later enters into a forbidden relationship with his colleague Julia and starts to remember what life was like before the Party came to power.

Nineteen Eighty-Four has become a classic literary example of political and dystopian fiction. It also popularised the term "Orwellian" as an adjective, with many terms used in the novel entering common usage, including "Big Brother", "doublethink", "Thought Police", "thoughtcrime", "Newspeak", and "2 + 2 = 5". Parallels have been drawn between the novel's subject matter and real life instances of totalitarianism, mass surveillance, and violations of freedom of expression among other themes. Time included the novel on its list of the 100 best English-language novels from 1923 to 2005, and it was placed on the Modern Library's 100 Best Novels list, reaching number 13 on the editors' list and number 6 on the readers' list. In 2003, it was listed at number eight on The Big Read survey by the BBC.

Eric Arthur Blair (25 June 1903 – 21 January 1950), known by his pen name George Orwell, was an English novelist, essayist, journalist and critic. His work is characterised by lucid prose, biting social criticism, total opposition to totalitarianism, and outspoken support of democratic socialism.Orwell produced literary criticism and poetry, fiction and polemical journalism. He is known for the allegorical novella Animal Farm (1945) and the dystopian novel Nineteen Eighty-Four (1949). His non-fiction works, including The Road to Wigan Pier (1937), documenting his experience of working-class life in the north of England, and Homage to Catalonia (1938), an account of his experiences soldiering for the Republican faction of the Spanish Civil War (1936–1939), are as critically respected as his essays on politics and literature, language and culture. In 2008, The Times ranked George Orwell second among "The 50 greatest British writers since 1945".Orwell's work remains influential in popular culture and in political culture, and the adjective "Orwellian"—describing totalitarian and authoritarian social practices—is part of the English language, like many of his neologisms, such as "Big Brother", "Thought Police", "Two Minutes Hate", "Room 101", "memory hole", "Newspeak", "doublethink", "unperson", and "thoughtcrime", as well as providing direct inspiration for the neologism "groupthink".