Catherine Eddowes (14 April 1842 – 30 September 1888) was the fourth of the canonical five victims of the notorious unidentified serial killer known as Jack the Ripper, who is believed to have killed and mutilated a minimum of five women in the Whitechapel and Spitalfields districts of London from late August to early November 1888.

Eddowes was murdered in the early hours of Sunday 30 September within the City of London. She was the second woman killed within an hour; the night having already seen the murder of Elizabeth Stride within the jurisdiction of the Metropolitan Police. These two murders are commonly referred to as the "double event"; a term which originates from the content of the "Saucy Jacky" postcard received at the Central News Agency on 1 October.

Part of a left human kidney, accompanied by a letter addressed From Hell and postmarked 15 October, was later sent to the chairman of the Whitechapel Vigilance Committee, George Lusk. The author of this letter claimed the section of kidney was from Eddowes, whose left kidney had been removed, and that he had fried and eaten the other half. Most experts, however, do not believe this kidney actually originated from Eddowes's body.