But new research has revealed she may have been Dublin's first female serial killer.
In fact, she was executed for the murders of at least five men whose bodies were found hidden in a brothel she owned in Dublin. It was widely accepted she was executed in 1746.
But the actual date of her public execution has now been revealed to be January 7, 1761 -- the 250th anniversary of her public burning at the stake was yesterday. She was partially hanged and then publicly burned alive in Baggot Street in the city.
The amazing true version of the events will be broadcast as No Smoke Without Hellfire on Dublin South 93.9 FM Community Radio on Wednesday next, January 12, at 4pm.
Producer and presenter Eamon McLoughlin told the Herald he was fascinated by new evidence unearthed during research work. His fellow researcher Phil O'Grady made the discovery while examining contemporary newspaper accounts in the National Archives.
Mr McLoughlin said: "This series debunks the tale, passed on down the centuries, that Simon Luttrell, known as Lord Carhampton, was the principle cause of her execution."
Popular belief held that Darkey Kelly, whose real name was Dorcas Kelly, ran the Maiden Tower brothel in Copper Alley, off Fishamble Street. She was supposed to have become pregnant with the child of city sheriff Simon Luttrell, a member of the infamous Hellfire Club, and demanded financial support.
Folklore maintained he responded by accusing her of witchcraft and of killing her baby in a satanic ritual even though a body was never found. She was burned at the stake. Part of this version is contained in a mural in the modern-day Darkey Kelly pub in Fishamble Street.
Newly revealed contemporary accounts reveal the real Dorcas Kelly was actually accused of killing shoemaker John Dowling and investigators then found the bodies of five men hidden in vaults in her brothel. Prostitutes reportedly rioted in Copper Alley following her execution.
Mr McLoughlin said: "Women in 18th-century Ireland were second class citizens and the execution of prisoners reflected that blatant sexism.
"Men found guilty of murder were just hanged, whereas women were throttled first, then burnt alive."
The Darkey Kelly case probably became confused with another sensational news story in the 1780s when Simon Luttrell's son Henry, who also had the title Lord Carhampton, allegedly raped a young teenage girl in a brothel. The girl was procured for him by brothel-keeper Maria Lewellyn. Lewellyn was described as Darkey Kelly's sister.
Henry Luttrell reportedly had the young girl and her parents falsely imprisoned. The girl's mother died in prison. Luttrell's charges against the girl and her family were later dismissed in court.
The radio programme also documents the activities of the Hellfire Club members in Dublin which included allegations that leading member Lord Santry often murdered "servants, porters and dwarves."