Under the Banner of Heaven: A Story of Violent Faith is a nonfiction book by author Jon Krakauer, first published in July 2003. He investigated and juxtaposed two histories: the origin and evolution of The Church of Jesus Christ of Latter-day Saints and a modern double murder committed in the name of God by brothers Ron and Dan Lafferty, who subscribed to a fundamentalist version of Mormonism.

Jon Krakauer is an American writer and mountaineer. He is the author of bestselling non-fiction books—Into the Wild; Into Thin Air; Under the Banner of Heaven; and Where Men Win Glory: The Odyssey of Pat Tillman—as well as numerous magazine articles. He was a member of an ill-fated expedition to summit Mount Everest in 1996, one of the deadliest disasters in the history of climbing Everest.