"At Swim-Two-Birds" is a novel by Irish writer Flann O'Brien, first published in 1939. The novel is known for its unconventional structure and its use of metafiction, in which the characters within the story are aware that they are fictional. The novel follows the story of a college student who is writing a novel about a man named Dermot Trellis, who is himself writing a novel about a group of characters, including a group of mischievous Irish gods. The novel is highly regarded for its wit, humor, and clever use of language, and is considered a classic of modernist literature.