Omensetter's Luck is a novel by William H. Gass, published in 1966. In his Salon article naming five overlooked American novels written after 1960, novelist David Foster Wallace called Omensetter's Luck Gass's "least avant-gardeish, and his best."And Susan Sontag wrote, "William Gass has written an extraordinary, stunning, beautiful book. I admire him and it very much."

Omensetter's Luck takes place in the 1890s in the fictitious town of Gilean, Ohio. The story is bookended by the story of Brackett Omensetter who arrives with his family to settle down. The middle (and the bulk) of the novel is devoted to the spiritual and mental degradation of the town's priest, Jethro Furber, who is jealous of Omensetter's magnetic personality and the luck that seems to underpin Omensetter's existence.

After a meeting to receive his monthly rent, Omensetter's landlord, Henry Pimber, disappears and is found much later, dead. Omensetter's luck changes soon after, forcing him to abandon Gilean, leaving the locals to question the role of Omensetter in Pimber's death.

William H. Gass (born July 30, 1924) is an American novelist, short story writer, essayist, critic, and former philosophy professor.