Uncle Silas, subtitled "A Tale of Bartram Haugh", is an 1864 Victorian Gothic mystery-thriller novel by the Irish writer J. Sheridan Le Fanu.

It is an early example of the locked-room mystery subgenre, rather than 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.

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 three-volume novel from the London publisher Richard Bentley.

Through her father and her worldly, cheerful cousin, Lady Monica Knollys, she gradually learns more regarding her uncle, Silas Ruthyn, a black sheep of the family whom she has never met; once an infamous rake and gambler, he is now apparently a fervently reformed Christian.

Lady Knollys, together with Austin's executor and fellow Swedenborgian, Dr. Bryerly, attempts in vain to overturn the codicil, realizing its dangerous implications for the young heiress; despite their efforts, Maud consents willingly to spending the next three and a half years at Bartram-Haugh.

Maud initially finds life at Bartram-Haugh strange but not unpleasant, despite ominous signs such as the uniformly unfriendly servants and Silas's malevolent factotum, the one-legged Dickon Hawkes.

Later that night, Dudley scales the building and enters the unlit room, which is the one in which the supposed suicide took place; the window he uses is set upon concealed hinges that allow it to be opened only from the outside.

Maud is happily married to the charming and handsome Lord Ilbury and ends her recollections on a philosophical note: This world is a parable—the habitation of symbols—the phantoms of spiritual things immortal shown in material shape.

May the blessed second-sight be mine—to recognise under these beautiful forms of earth the ANGELS who wear them; for I am sure we may walk with them if we will, and hear them speak!Uncle Silas remains Le Fanu's best-known novel.

There are also strong connections between Uncle Silas and some of Wilkie Collins' novels, especially The Woman in White; both writers, while recognisably within the Gothic tradition, depict heroines who are far more highly developed than the persecuted maidens of Ann Radcliffe and others.