Paul Atreides (/əˈtreɪɪdiːz/; later known as Paul Muad'Dib, and later still as The Preacher) is a fictional character in the Dune universe created by Frank Herbert. He is a main character in the first two novels in the series, Dune (1965) and Dune Messiah (1969), and returns in Children of Dune (1976). The character is brought back as two different gholas in the Brian Herbert and Kevin J. Anderson novels which conclude the original series, Hunters of Dune (2006) and Sandworms of Dune (2007), and appears in the prequels Paul of Dune (2008) and The Winds of Dune (2009). According to Brian Herbert, Frank Herbert's son and biographer, House Atreides was based on the heroic but ill-fated Greek mythological house of Atreus.

A primary theme of Dune and its sequels is Frank Herbert's warning about society's tendencies to "give over every decision-making capacity" to a charismatic leader. He said in 1979, "The bottom line of the Dune trilogy is: beware of heroes. Much better [to] rely on your own judgment, and your own mistakes." Paul rises to leadership through military strategy and political maneuvering, but his superhuman powers and ability to fit himself into pre-existing religious infrastructure allow him to force himself upon mankind as their messiah. As "Muad'Dib", Paul becomes the central figure of a new religion, and reluctantly unleashes a bloody jihad in his name across the universe. Paul struggles with the idea of potentially seizing divine control over his newly minted empire, but by following the path of his destiny, he escapes from the burden of it. He lets an assassination plot against him play out, blinding him, and follows the Fremen tradition of the blind going out into the desert to die. The burden of the empire is then placed upon Paul's sister Alia, and his children Leto II and Ghanima. Paul later reappears as the Preacher, seeking to end the religion founded around him, but is assassinated.

Paul is portrayed by Kyle MacLachlan in David Lynch's 1984 film adaptation, by Alec Newman in the 2000 Dune miniseries and its 2003 sequel, and by Timothée Chalamet in the 2021 Denis Villeneuve film Dune and its 2024 sequel. Chalamet is confirmed to reprise the role in the upcoming sequel film, Dune: Part Three (2026).

The son of Duke Leto Atreides and the Lady Jessica, Paul is the heir of House Atreides, an aristocratic family that rules the planet Caladan. Jessica is a Bene Gesserit and an important key in the Bene Gesserit breeding program. According to the breeding program, she was to produce a daughter, who would be bred with Feyd-Rautha, a nephew of Baron Vladimir Harkonnen. However, Jessica falls in love with Leto and grants him the son he desires. Although Paul is a boy, Jessica gives him some training in the Bene Gesserit ways, including enhanced observation and the Sisterhood's specialized martial art. Initially described as "small for his age", Paul has secretly undergone the early Mentat training, and is also schooled in weapon use by Gurney Halleck and Duncan Idaho.

In Dune (1965), Paul is fifteen years old; the Padishah Emperor Shaddam IV orders the family to leave Caladan and govern the desert planet Arrakis (known as Dune), though Paul's father Duke Leto is in full knowledge that the Emperor is colluding with House Harkonnen to destroy House Atreides as a perceived threat to the throne. On Dune, the family is betrayed by their Suk doctor, Wellington Yueh. He disables the House defensive shields, allowing the Imperial Sardaukar troops, dressed in Harkonnen uniforms, to capture Duke Leto and Thufir Hawat and to kill most of the Atreides army. Duncan sacrifices himself while attempting to hold off the Sardaukar and ensures Paul's escape. His betrayal motivated by the Baron's capture and torture of his Bene Gesserit wife, Yueh implants a poisonous gas capsule concealed within a false tooth on Duke Leto after his capture and instructs Leto to use it to kill the Baron. Shortly afterward, the Baron has Yueh murdered. Upon meeting Baron Harkonnen and his twisted Mentat Piter De Vries, Leto bites down on the capsule. He succeeds in killing De Vries—and himself—but not the Baron. Fed a poison for which only the Baron has the antidote, Hawat is forced to serve as the new Harkonnen Mentat. With some help from Yueh, Paul and Jessica escape into the desert.

They flee to the Fremen, who see in Paul the Lisan al-Gaib or "the Voice from the Outer World", a prophet they call the Mahdi whom they believe is "The One Who Will Lead Us to Paradise". Paul and Jessica take shelter in Sietch Tabr, a Fremen settlement led by the naib, Stilgar. Paul and his mother train the Fremen in weapon use and martial arts, creating a formidable army. When Paul is accepted into the Fremen tribe, he is given the secret "sietch name" Usul, the Fremen word meaning "the base of the pillar". He chooses "Paul Muad'Dib" as his common name of manhood, to be used openly. Muad'Dib is the name of the adapted kangaroo mouse of Arrakis, and Stilgar relates that Paul's choice pleases the Fremen:

Muad'Dib is wise in the ways of the desert. Muad'Dib creates his own water. Muad'Dib hides from the sun and travels in the cool night. Muad'Dib is fruitful and multiplies over the land. Muad'Dib we call 'instructor-of-boys.' That is a powerful base on which to build your life, Paul Muad'Dib, who is Usul among us.

Paul leads a Fremen campaign of resistance against Harkonnen rule. He and Chani, daughter of Liet-Kynes, take each other as mates and produce a son, named Leto in honor of Paul's father. Paul also reunites with Gurney Halleck, who had sought refuge with smugglers after the Harkonnen attack. In a bid to unlock his latent powers, Paul undergoes the process of spice agony via the consumption of the Water of Life. He survives, although barely, and the ordeal gives him knowledge of his male and female ancestors; this proves Paul is the Kwisatz Haderach.