The story of the Cock Lane ghost attracted mass public attention in eighteenth-century England before being exposed as a hoax.

Cock Lane is a short alleyway adjacent to London's Smithfield market and only a few minutes' walk from St Paul's Cathedral. In the eighteenth century this district housed London's working poor. It was this environment that, in January 1762, gave rise to an extraordinary scandal that fascinated the London public.

At the centre of the story was William Kent, a young man from Norfolk who became involved with two daughters from the same family. The first, Elizabeth Lynes, he married, but she died in childbirth; a few months later, William eloped to London with his dead wife's sister, Fanny Lynes. Here Kent and his new wife lodged in Cock Lane at the house of a clerk named William Parsons. Kent loaned money to Parsons which the latter refused to repay, leading Kent to sue him. While Kent was away on a business trip, Fanny claimed she heard mysterious scratching in the bedroom she shared with Parsons' daughter, Elizabeth. She believed it was the ghost of her sister warning her of her impending death. The Kents moved to new lodgings where, shortly after, Fanny died of smallpox.

The mysterious scratchings in Elizabeth Parsons' bedroom increased after Fanny Kent's death. William Parsons began communicating with the "ghost" using yes/no questions and a system of knocking for the answer and thus supposedly determined that they were in contact with the ghost of Fanny Kent, who claimed that she had died not of smallpox, but of arsenic poisoning in a premeditated murder by her husband, William. The house in Cock Lane became a popular attraction, with Parsons charging sightseers an entrance fee to "talk" with the ghost.