Catherine Hayes (1690 – 9 May 1726), sometimes spelled Catharine Hayes, was an English traitor who was burned at the stake for committing petit treason by killing her husband.
Catherine Hall was born near Birmingham in 1690. At the age of 16, she married John Hayes, a carpenter. The couple moved to London and set up a small shop in Oxford Road, Tyburn, while renting lodgings. Towards the end of 1725, two men named Wood and Billings lodged with the couple. Catherine Hayes was by then the mother of 12 children. She was intimate with the new lodgers, and the three lovers decided to kill John Hayes. On 1 March 1726, they got him drunk and then killed him. They cut up the body and flung a trunkful of body parts into a pond at Marylebone. The head was cast into the Thames and was found the next day. It was displayed in the churchyard of St Margaret's, Westminster, for several days, which resulted in John Hayes being identified.
On 24 March the trunk and limbs were discovered. Catherine Hayes and Billings had meanwhile been arrested on a warrant. Wood was captured shortly afterwards, and confessed. Billings then admitted his complicity, but Hayes denied all knowledge of the murder. At the trial, Hayes pleaded 'not guilty', but was convicted of petty treason, and sentenced to be burned at the stake. Wood and Billings were sentenced to be hanged. The case excited much popular attention, and many noblemen and gentlemen attended the trial.
Before 9 May, the day fixed for the execution, Wood died in Newgate Prison. Hayes unsuccessfully tried to poison herself. On 9 May, she was tied to a stake at Tyburn with a halter round her neck. One early report stated that "the executioner was foiled in an endeavour to strangle her by the burning of the rope, and the woman was finally killed by a piece of wood which was thrown at her head and dashed out her brains". Later it was stated that Hayes was "the last woman in England to be burnt alive for petty treason (though the burning of women's bodies after execution continued until 1790)". Billings was hanged in chains in Marylebone Fields. Ballads were written about Hayes' crime, and a correspondent of the London Journal compared the murder of John Hayes to the play Arden of Feversham. William Makepeace Thackeray based his story of Catherine, which first appeared in Fraser's Magazine 1839–40, on the career of Catherine Hayes.
The story of John and Catherine Hayes was told in the 28 October 1953 episode of the CBS radio series Crime Classics entitled "John Hayes, His Head, and How They Were Parted." Catherine Hayes was portrayed by Betty Harford, while John Hayes was played by Alistair Duncan.