Uncle Silas is a Victorian Gothic mystery-thriller novel by the Irish writer J. Sheridan Le Fanu. It is notable as one of the earliest examples of the locked room mystery subgenre. It is not a novel of the supernatural (despite a few creepily ambiguous touches), but does show a strong interest in the occult and in the ideas of Emanuel Swedenborg, a Swedish scientist, philosopher and Christian mystic.
Like many of Le Fanu's novels, it grew out of an earlier short story, "A Passage in the Secret History of an Irish Countess" (1839), which he also published as "The Murdered Cousin" in the 1851 collection Ghost Stories and Tales of Mystery. The setting of the original story was Irish; presumably it was changed to Derbyshire for the novel because this would appeal more to a British audience. It was first serialized in the Dublin University Magazine in 1864, under the title Maud Ruthyn and Uncle Silas, and appeared in December of the same year as a triple-decker novel from the London publisher Richard Bentley.
