St. Leon: A Tale of the Sixteenth Century (1799) is eighteenth-century British philosopher William Godwin's second novel.
Following the success of Things as They Are; or, The Adventures of Caleb Williams (1794), Godwin searched for a topic that would capture his imagination as much as his first novel. St. Leon is the tale of a French aristocrat, Count Reginald de St. Leon, who loses his wealth gambling and experiences guilt that drives him almost to madness. He accepts, from a dying stranger, the gift of the secret of the elixir of life and of the power of multiplying wealth, and consequently is forced to wander separated from humankind.