Satire is a literary technique of writing or art which principally ridicules its subject (individuals, organizations, states) often as an intended means of provoking or preventing change. In Celtic societies, it was thought a bard's satire could have physical effects, similar to a curse. A satirist is one who satirizes.

Satire is not exclusive to any viewpoint. Parody is a form of humor that imitates another work of art in an exaggerated fashion for comic effect, usually deriding the subject of the parody in the process. Although the techniques of satire and parody often overlap, they are not synonymous. Satires need not be humorous - indeed, they are often tragic - while parodies are almost inevitably humorous. Parodies are imitative by definition, while satires need not be. Humorous satires often base the humor on the juxtaposition between the satire and reality. The main intent of satire is political, social, or moral and not comic. The humor of such a satire tends to be subtle, using irony and deadpan humor liberally.

Common examples of satire include:

Diminution: Reduces the size of something in order that it may be made to appear ridiculous or in order to be examined closely and have its faults seen close up. For example, treating the Canadian Members of Parliament as a squabbling group of little boys is an example of diminution. The first portion of Gulliver's Travels, set in the ficticious land of Liliput, is a diminutive satire.

Inflation: A common technique of satire is to take a real-life situation and exaggerate it to such a degree that it becomes ridiculous and its faults can be seen, and thus satirical. For example, two boys arguing over a possession of a car can be inflated into an interstellar war. The Rape of the Lock is an example of inflation.

Juxtaposition: Places things of unequal importance side by side. It brings all the things down to the lowest level of importance on the list. For example, if a guy says his important subjects in school include Calculus, Computer Science, Physics, and Girl-watching, he has managed to take away some of the importance of the first three. The Rape of the Lock is also an example of juxtaposition.

Notable examples of satire are:

• Ovid The Art of Love
• Juvenal (c. A.D. 55-140) 16 Satires
• the Satirae (c. A.D. 50) by Petronius
• A Tale of a Tub, Gulliver's Travels and A Modest Proposal by Jonathan Swift, harsh views of the world
• Candide by Voltaire, satirizing optimism
• Erewhon by Samuel Butler II, a utopia, a form that is common in satire.
• Nineteen Eighty-Four by George Orwell, a dystopia, also common in satire.
• Ubu Roi (or King Turd), by Alfred Jarry, cacotopia
• Penguin Island by Anatole France, utopia
• Brave New World by Aldous Huxley, dystopia
• Mark Twain's later works, notably The Man Who Corrupted Hadleyburg
• Wise Blood by Flannery O'Connor, satirizing contemporary religious attitudes
• C. Northcote Parkinson's satires on bureaucracy.
• Thomas Nast's political cartoons against Boss Tweed
• The Landover Baptist Church, an internet parody of Christian fundamentalism
• Al Franken is a writer of political satire.
• Stanley Kubrick's movies Doctor Strangelove and A Clockwork Orange.
• Robert Clark Young's controversial novel One of the Guys
• Dario Fo's Accidental Death of an Anarchist
• le Canard Enchaîné publishes satiric cartoons and columns along with well-researched information on French political or economic life.
• Cat's Cradle by Kurt Vonnegut Jr. is a political satire, adopting a sci-fi motif.
• Fight Club by Chuck Palahniuk is a satire of violence, fascism and nihilism.
• Chris Morris's Brass Eye, a satire of Britsh news programmes
• The Onion and The Daily Show, satires of the American news media

Some works of satire are subtle enough in their exaggeration that they still seem believable to many people. The satiric nature of these works may be lost on the public at large, and there have been instances where the author or producers of a satirical work have been harshly criticized as a result. In 2002 the British network Channel 4 aired a satiric mockumentary entitled Paedogeddon in the Brass Eye series, which was intended to mock and satirize the fascination of modern journalism with child molestors and paedophiles. The TV network received an enormous number of complaints from members of the public, who were outraged that the show would mock a subject considered by many to be too "serious" to be the subject of humor. The movie This is Spinal Tap, a spoof of rockumentaries, about a fictitious and ridiculous hard rock band was mistaken for a non-fiction by some critics.

On occasion, satire can cause social change when used to make a political or social point (although simply revealing absurdities to the public, as opposed to the quality of the satire, may be the actual cause of any consequences). For instance, the comic strip Doonesbury satirized a Florida county that had a racist law that minorities had to have a passcard in the area; the law was soon repealed with an act nicknamed the Doonesbury Act. In the 2000 Canadian federal election campaign, a Canadian Alliance proposal for a mechanism to require a referendum in response to a petition of sufficient size was satirized by the television show This Hour Has 22 Minutes so effectively that it was discredited and soon dropped.

Satire enjoyed a renaissance in the UK in the early 1960s with the Satire Boom, led by such luminaries as Peter Cook, Alan Bennett, Jonathan Miller, David Frost, Eleanor Bron and Dudley Moore and the television programme That Was The Week That Was.