The Damnation of Theron Ware (published in England as Illumination) is an 1896 novel by American author Harold Frederic. The novel reveals a great deal about late 19th century provincial America, religious life, and the depressed state of intellectual and artistic culture in small towns. It is similar to Samuel Butler's The Way of All Flesh and Sinclair Lewis's Elmer Gantry. It is written in a realistic style.

The novel centers on the life of a Methodist pastor named Theron Ware who has recently moved to a fictional small town in the Adirondack Mountains of upstate New York, which Frederic modeled after Utica, New York. A promising young pastor recently married, Theron has a number of experiences that cause him to begin to question the Methodist religion, his role as a minister and even the very existence of God. His moral decline (or illumination) is heightened through his dealings with Father Forbes, the town's Catholic priest; Dr. Ledsmar, a local atheist, philosopher, and man of science; and Celia Madden, a local Irish Catholic girl, a species of aesthete, with whom Theron becomes hopelessly infatuated. In the end, these three "advanced" characters find Theron a bore, and tell him so. He goes on a binge, and is saved by Brother and Sister Soulsby, common-sensical fund-raisers for Methodist congregations. Their feet are on the ground, and they pack Theron and his wife off to the new state of Washington, where—who knows?--he might end up in politics.