The Cleveland Torso Murderer, also known as the Mad Butcher of Kingsbury Run, was an unidentified serial killer who operated in Cleveland, Ohio, United States, in the 1930s. The killings were characterized by the dismemberment of thirteen known victims and the disposal of their remains in the impoverished neighborhood of Kingsbury Run. Most victims came from an area east of Kingsbury Run called "The Roaring Third" or "Hobo Jungle", known for its bars, gambling dens, brothels, and vagrants. Despite an investigation of the murders, which at one time was led by famed lawman Eliot Ness, the murderer was never apprehended. In 2024, the Cuyahoga County Medical Examiner's Office teamed up with the DNA Doe Project to exhume some of the victims and use investigative genetic genealogy to identify them.

The official number of murders attributed to the Cleveland Torso Murderer is twelve, although recent research has shown there could have been as many as twenty or more. The twelve known victims were killed between 1935 and 1938. Some investigators, including lead detective Peter Merylo, believed that there may have been thirteen or more victims in the Cleveland, Youngstown, and Pittsburgh areas between the 1920s and 1950s. Two strong candidates for addition to the "official" list are the unknown victim nicknamed the "Lady of the Lake", found on September 5, 1934, and Robert Robertson, found on July 22, 1950.

The victims of the Torso Murderer were usually drifters whose identities were never determined, although there were a few exceptions. Victims numbers 2, 3, and 8 were identified as Edward Andrassy, Florence Polillo, and possibly Rose Wallace, respectively. Andrassy and Polillo were both identified by their fingerprints, while Wallace was tentatively identified via her dental records. The victims appeared to be lower class individuals–easy prey during the Great Depression. Many were known as "working poor", who had nowhere else to live but the ramshackle shanty towns, or "Hoovervilles", in the area known as the Cleveland Flats.

The Torso Murderer always beheaded and often dismembered their victims, occasionally severing the victim's torso in half or severing their appendages. In many cases the cause of death was the decapitation or dismemberment itself. Most of the male victims were castrated. Some victims showed evidence of chemical treatment being applied to their bodies, which caused the skin to become red, tough and leathery. Many were found after a considerable period of time following their deaths, occasionally in excess of a year. In an era when forensic science was largely in its infancy, these factors further complicated identification, especially since the heads were often undiscovered.

During the time of the "official" murders, Eliot Ness, leader of The Untouchables, was serving as Cleveland's Public Safety Director, a position with authority over the police department and ancillary services, including the fire department. Ness contributed to the arrest and interrogation of one of the prime suspects, Dr. Francis Sweeney, and personally conducted raids into shantytowns and eventually burned them down. Ness's reasoning for doing so was to catalogue fingerprints to easily identify any new victims, and to get possible victims out of the area in an attempt to stop the murders.

Four days after the burning, on August 22, 1938, Ness launched an equally draconian operation where he personally dispatched six two-man search teams on a large area of Cleveland, stretching from the Cuyahoga River to East 55th Street to Prospect Avenue, under the guise of conducting city fire inspections. While the search never turned up any new or incriminating information that could lead to the arrest and conviction of the Torso Murderer, it did serve to focus renewed public attention on the inadequate and unsanitary living conditions in the downtown area. Teams uncovered hundreds of families living in hazardous fire traps without toilets or running water. The interests of social reform did ultimately come to light even if those of law enforcement did not. At one point, the Torso Murderer taunted Ness by placing the remains of two victims in full view of his office at City Hall. The man who Ness believed to be the killer would later also provoke him by sending postcards.

Most researchers consider there to be twelve victims, although some have counted as many as twenty or forty. Evidence suggests a woman dubbed the "Lady of the Lake" could be included. There was a second victim who was also considered to be a victim of the Torso Murderer in 1950 named Robert Robertson due to the fact that his head was also cut off in a manner very similar to the confirmed victims. Only three victims were positively identified; the other ten were six John Does and four Jane Does. Exhumations of unidentified victims started in August 2024 after the Cuyahoga County Medical Examiner’s Office partnered with the DNA Doe Project to identify the victims through genetic genealogy.

Edward Anthony Andrassy, age 29, was discovered on September 23, 1935, in a gully at the base of Jackass Hill where East 49th Street dead-ends into Kingsbury Run. Andrassy's head was discovered buried near the rest of his body, which was found to be emasculated and wearing only socks. The autopsy report stated that Andrassy was decapitated in the mid-cervical region with a fracture of the mid-cervical vertebrae. The coroner also noted that he had rope burns around his wrists. The cause of death was decapitation; hemorrhage and shock. He had been dead for two to three days. At one time, Andrassy had been an orderly in the psychiatric ward at Cleveland City Hospital. However, at the time of his death, he was unemployed and had no visible means of financial support.