The Crooked Hinge is a mystery novel (1938) by detective novelist John Dickson Carr.

It combines a seemingly impossible throat-slashing with elements of witchcraft, an automaton modelled on Maelzel's Chess Player, and the story of the Tichborne Claimant.

In a poll of 17 detective story writers and reviewers, this novel was voted as the fourth best locked room mystery of all time.

John Farnleigh is a wealthy young man married to his childhood love, and a survivor of the Titanic disaster.

Later, a mysterious automaton reaches out to touch a housemaid, who nearly dies of fright, and a thumbograph (an early toy associated with the taking of fingerprints) disappears from a locked library.