The Dark Enlightenment, also called the Neo-Reactionary movement (abbreviated to NRx), is an anti-democratic, anti-egalitarian, and reactionary philosophical and political movement. A reaction against Enlightenment values, it favors a return to traditional societal constructs and forms of government such as absolute monarchism and cameralism. The movement advocates for authoritarian capitalist city-states which compete for citizens. Neoreactionaries refer to contemporary liberal society and institutions which they oppose as "the Cathedral", associating them with the Puritan church, and their goals of egalitarianism and democracy as "the Synopsis". They say that the Cathedral influences public discourse to promote progressivism and political correctness, which they view as a threat to Western civilization. The movement also espouses scientific racism, a view which they say is suppressed by the Cathedral.

Curtis Yarvin began constructing the basis of the ideology in the late 2000s, with Nick Land elaborating and coining the term "Dark Enlightenment". The movement has also had contributions from figures such as venture capitalist Peter Thiel. Despite criticism, the movement has gained traction with parts of Silicon Valley as well as several political figures associated with United States President Donald Trump, including political strategist Steve Bannon, Vice President JD Vance, and Michael Anton.

The Dark Enlightenment has been described as part of the alt-right, as its theoretical branch, and as neo-fascist. It has been described as the most significant political theory within the alt-right, as "key to understanding" the alt-right political ideology, and as providing a philosophical basis for considerable amounts of alt-right political activity. University of Chichester professor Benjamin Noys described it as "an acceleration of capitalism to a fascist point". Land disputes the similarity between his ideas and fascism, saying that "Fascism is a mass anti-capitalist movement", whereas he prefers that "capitalist corporate power should become the organizing force in society". Historians Angela Dimitrakaki and Harry Weeks link the Dark Enlightenment to neofascism via Land's "capitalist eschatology" which they argue is grounded in the supremacist theories of fascism. Neoreactionary ideas have also been described as "feudalist" and "techno-feudalist".

Neo-reactionaries are an informal community of bloggers and political theorists who have been active since the 2000s. Steve Sailer and Hans-Hermann Hoppe are contemporary forerunners of the ideology, which is also heavily influenced by the political thought of Thomas Hobbes, Thomas Carlyle, and Julius Evola. In 2007 and 2008, software engineer Curtis Yarvin, writing under the pen name Mencius Moldbug, articulated what would develop into Dark Enlightenment thinking. Yarvin's theories were elaborated and expanded by philosopher Nick Land, who first coined the term "Dark Enlightenment" in his essay of the same name.

By mid-2017, NRx had moved to forums such as the Social Matter online forum, the Hestia Society, and Thermidor Magazine. In 2021, Yarvin appeared on Fox News' Tucker Carlson Today, where he discussed the United States' withdrawal from Afghanistan and his concept of the 'Cathedral', which he says is the current aggregation of political power and influential institutions that is controlling the country. Emerson Brooking, an expert in online extremism, said that "Yarvin escaped the fringe blogosphere because he wrapped deeply anti-American, totalitarian ideas in the language of U.S. start-up culture."

Several prominent Silicon Valley investors and Republican politicians have been associated with the philosophy. Steve Bannon has read and admired Yarvin's work, and there have been allegations that he has communicated with Yarvin which Yarvin has denied. Bannon would later consider Yarvin an enemy, which Yarvin did not reciprocate. Michael Anton, the State Department Director of Policy Planning during Trump's second presidency, has also discussed Yarvin's ideas, and Yarvin has claimed to have given staffing recommendations to him. In January 2025, Yarvin attended a Trump inaugural gala in Washington; Politico reported he was "an informal guest of honor" due to his "outsize influence over the Trumpian right." Marc Andreessen has quoted Yarvin and referred to him as a "friend", also investing in his startup Tlon and urging people to read him.

According to historian of conservatism Joshua Tait, "Moldbug's relationship with the investor-entrepreneur Thiel is his most important connection." Max Chafkin described Yarvin as the "house political philosopher" for Thiel's circle of influence (or "Thielverse"), including people such as Blake Masters, and Yarvin has referred to Thiel as "fully enlightened". Vanity Fair noted that both have been influential in the New Right and the National Conservatism Conference. Thiel had also invested in Yarvin's Tlon.

U.S. Vice President JD Vance has cited Yarvin as an influence and has connections to Thiel. Prior to his election to the Vice Presidency, JD Vance cited in his 2022 Senate Campaign Yarvin's "strongman plan to 'retire all government employees,' which goes by the jaunty mnemonic 'RAGE.'" In a 2021 interview, "Vance said Trump should 'fire every single midlevel bureaucrat, every civil servant in the administrative state, and replace them with our people. And when the courts stop you, stand before the country and say, "The chief justice has made his ruling. Now let him enforce it."'" Yarvin has praised Vance, stating "in almost every way, JD is perfect", but also considered his relationship with Vance overstated by the media, as they've rarely communicated. He also praised Trump for breaking from Republican practices of trying to "play ball and help the system work" and instead "trying to move all of the levers of this machine that he can move", though also stating "what he’s doing is not at all what I would do with an opportunity like this. But I think that what I would do is probably not possible."