Catch-22 is a satirical novel by Joseph Heller, first published in 1961. It follows the story of Yossarian, a U.S. Army Air Forces B-25 bombardier, and his attempts to survive the insanity of World War II. The novel is set on the fictional island of Pianosa, off the coast of Italy, and is populated by a variety of characters, including Yossarian's squadron mates, the chaplain, and the mysterious Colonel Cathcart.

The novel's title refers to a "catch-22," a paradoxical situation in which a person is trapped by a self-contradictory rule. In the novel, the catch-22 is that a person can be declared insane if they request to be removed from combat duty, but if they do not request to be removed, they are considered sane and must continue to fly missions.

The novel follows Yossarian's attempts to survive the war, as he is constantly faced with the absurdities of military bureaucracy and the insanity of war. He is also faced with the moral dilemma of whether or not to obey orders that he believes are immoral. Yossarian's attempts to survive the war are often thwarted by the actions of his superiors, such as Colonel Cathcart, who continually increases the number of missions that Yossarian and his squadron must fly.

The novel is filled with dark humor and satire, as Heller uses the absurdities of war to illustrate the insanity of the situation. The novel also explores themes of morality, as Yossarian is forced to confront the moral implications of his actions.

The novel has been widely praised for its wit and insight into the absurdity of war. It has been adapted into a film, a play, and an opera, and has been cited as an influence on many other works of literature. Catch-22 remains one of the most influential and acclaimed novels of the 20th century.