Political correctness (adjectivally "politically correct"; commonly abbreviated to P.C.) is a term used to describe language, policies, or measures that are intended to avoid perceived offense or disadvantage to members of particular groups in society. Since the late 1980s, the term has been used to describe a preference for inclusive language and avoidance of language or behavior that can be seen as excluding, marginalizing, or insulting to groups of people disadvantaged or discriminated against, particularly groups defined by ethnicity, sex, gender, sexual orientation, or disability. In public discourse and the media, the term’s use is generally pejorative, with an implication that these policies are excessive or unwarranted. It can also be humorous, or ironic in nature.

The phrase politically correct first appeared in the 1930s, when it was used to describe dogmatic adherence to ideology in totalitarian regimes, such as Nazi Germany and Soviet Russia. Early usage of the term politically correct by leftists in the 1970s and 1980s was as self-critical satire; usage was ironic, rather than a name for a serious political movement. It was considered an in-joke among leftists used to satirise those who were too rigid in their adherence to political orthodoxy. The modern pejorative usage of the term emerged from conservative criticism of the New Left in the late 20th century, with many describing it as a form of censorship.

Commentators on the political left in the United States contend that conservatives use the concept of political correctness to downplay and divert attention from substantively discriminatory behavior against disadvantaged groups. They also argue that the political right enforces its own forms of political correctness to suppress criticism of its favored constituencies and ideologies. In the United States, the term has played a major role in the culture war between liberals and conservatives.

Several researchers describe political correctness not only as a political label but also as a practice of linguistic reform aimed at reducing exclusionary or derogatory expressions in public language, often in line with egalitarian or inclusive norms. Geoffrey Hughes and Norman Fairclough both note that these language reforms are intertwined with broader social efforts to reshape public discourse and social relations.

In the early-to-mid 20th century, the phrase politically correct was used to describe strict adherence to a range of ideological orthodoxies within politics. In 1934, The New York Times reported that Nazi Germany was granting reporting permits "only to pure 'Aryans' whose opinions are politically correct".

The term political correctness first appeared in Marxist–Leninist vocabulary following the Russian Revolution of 1917. At that time, it was used to describe strict adherence to the policies and principles of the Communist Party of the Soviet Union, that is, the party line. Later in the United States, the phrase came to be associated with accusations of dogmatism in debates between communists and socialists. According to American educator Herbert Kohl, writing about debates in New York in the late 1940s and early 1950s.

The term "politically correct" was used disparagingly, to refer to someone whose loyalty to the CP line overrode compassion, and led to bad politics. It was used by Socialists against Communists, and was meant to separate out Socialists who believed in egalitarian moral ideas from dogmatic Communists who would advocate and defend party positions regardless of their moral substance.

— "Uncommon Differences", The Lion and the Unicorn