"The Sphinx Without a Secret" is a short story by the Irish author Oscar Wilde. It was first published in the newspaper The World in May 1887. It appeared in print again in 1891 as part of the anthology Lord Arthur Savile's Crime and Other Stories.
The story centers around the relationship between a man, Lord Murchison, and a woman, Lady Alroy. Lady Alroy appears to have a mystery connected to her. She refuses to tell Lord Murchison what it is and he is unable to figure it out.