The Ripper murders mark an important watershed in the treatment of crime by journalists. Jack the Ripper was not the first serial killer, but his case was the first to create a worldwide media frenzy. Tax reforms in the 1850s had enabled the publication of inexpensive newspapers with wider circulation. These mushroomed in the later Victorian era to include mass-circulation newspapers as cheap as a halfpenny, along with popular magazines such as The Illustrated Police News which made the Ripper the beneficiary of previously unparalleled publicity.

In the mid-19th century, Britain experienced an influx of Irish immigrants who swelled the populations of the major cities, including the East End of London. From 1882, Jewish refugees from pogroms in Tsarist Russia and other areas of Eastern Europe emigrated into the same area. The parish of Whitechapel in London's East End became increasingly overcrowded. Work and housing conditions worsened, and a significant economic underclass developed. Robbery, violence, and alcohol dependency were commonplace, and the endemic poverty drove many women to prostitution. In October 1888, London's Metropolitan Police Service estimated that there were 62 brothels and 1,200 women working as prostitutes in Whitechapel. The economic problems were accompanied by a steady rise in social tensions. Between 1886 and 1889, frequent demonstrations led to police intervention and public unrest, such as that of 13 November 1887. Anti-semitism, crime, nativism, racism, social disturbance, and severe deprivation influenced public perceptions that Whitechapel was a notorious den of immorality. In 1888, such perceptions were strengthened when a series of vicious and grotesque murders attributed to "Jack the Ripper" received unprecedented coverage in the media.

In addition to the eleven Whitechapel murders, commentators have linked other attacks to the Ripper. In the case of "Fairy Fay", it is unclear whether the attack was real or fabricated as a part of Ripper lore. "Fairy Fay" was a nickname given to a victim allegedly found on 26 December 1887 "after a stake had been thrust through her abdomen", but there were no recorded murders in Whitechapel at or around Christmas 1887. "Fairy Fay" seems to have been created through a confused press report of the murder of Emma Elizabeth Smith, who had a stick or other blunt object shoved into her vagina. Most authors agree that the victim "Fairy Fay" never existed.

Scotland Yard published facsimiles of the "Dear Boss" letter and the postcard on 3 October, in the ultimately vain hope that someone would recognise the handwriting. Charles Warren explained in a letter to Godfrey Lushington, Permanent Under-Secretary of State for the Home Department: "I think the whole thing a hoax but of course we are bound to try & ascertain the Writer in any case." On 7 October 1888, George R. Sims in the Sunday newspaper Referee implied scathingly that the letter was written by a Journalist "to hurl the circulation of a newspaper sky high". Police officials later claimed to have identified a specific Journalist as the author of both the "Dear Boss" letter and the postcard. The Journalist was identified as Tom Bullen in a letter from Chief Inspector John Littlechild to George R. Sims dated 23 September 1913. A Journalist called Fred Best reportedly confessed in 1931 that he and a colleague at The Star had written the letters signed "Jack the Ripper" to heighten interest in the murders and "keep the Business alive".

"The Pinchin Street torso" was a headless and legless torso of an unidentified woman found under a railway arch in Pinchin Street, Whitechapel, on 10 September 1889. It seems probable that the murder was committed elsewhere and that parts of the dismembered body were dispersed for disposal.

Carrie Brown (nicknamed "Shakespeare", reportedly for quoting Shakespeare's sonnets) was strangled with clothing and then mutilated with a knife on 24 April 1891 in New York City. Her body was found with a large tear through her groin area and superficial cuts on her legs and back. No organs were removed from the scene, though an ovary was found upon the bed, either purposely removed or unintentionally dislodged. At the time, the murder was compared to those in Whitechapel, though the Metropolitan Police eventually ruled out any connection.

The concentration of the killings around weekends and public holidays and within a few streets of each other has indicated to many that the Ripper was in regular employment and lived locally. Others have thought that the killer was an educated upper-class man, possibly a Doctor or an aristocrat who ventured into Whitechapel from a more well-to-do area. Such theories draw on cultural perceptions such as fear of the medical profession, mistrust of modern science, or the exploitation of the poor by the rich. Suspects proposed years after the murders include virtually anyone remotely connected to the case by contemporary documents, as well as many famous names who were never considered in the police investigation. Everyone alive at the time is now dead, and modern authors are free to accuse anyone "without any need for any supporting historical evidence". Suspects named in contemporary police documents include three in Sir Melville Macnaghten's 1894 memorandum, but the evidence against them is circumstantial at best.

In the immediate aftermath of the murders and later, "Jack the Ripper became the children's bogey man." Depictions were often phantasmic or monstrous. In the 1920s and 1930s, he was depicted in film dressed in everyday clothes as a man with a hidden secret, preying on his unsuspecting victims; atmosphere and evil were suggested through lighting effects and shadowplay. By the 1960s, the Ripper had become "the symbol of a predatory aristocracy", and was more often portrayed in a top hat dressed as a gentleman. The Establishment as a whole became the villain, with the Ripper acting as a manifestation of upper-class exploitation. The image of the Ripper merged with or borrowed symbols from horror stories, such as Dracula's cloak or Victor Frankenstein's organ harvest. The fictional world of the Ripper can fuse with multiple genres, ranging from Sherlock Holmes to Japanese erotic horror.

Jack the Ripper features in hundreds of works of fiction and works which straddle the boundaries between fact and fiction, including the Ripper letters and a hoax Diary of Jack the Ripper. The Ripper appears in novels, short stories, poems, comic books, games, songs, plays, operas, television programmes, and films. More than 100 non-fiction works deal exclusively with the Jack the Ripper murders, making it one of the most written-about true-crime subjects. The term "ripperology" was coined by Colin Wilson in the 1970s to describe the study of the case by professionals and amateurs. The periodicals Ripperana, Ripperologist, and Ripper Notes publish their research.

There is no waxwork figure of Jack the Ripper at Madame Tussauds' Chamber of Horrors, unlike Murderers of lesser fame, in accordance with their policy of not modelling persons whose likeness is unknown. He is instead depicted as a Shadow. In 2006, BBC History magazine and its readers selected Jack the Ripper as the worst Briton in history.

The nature of the murders and of the victims drew attention to the poor living conditions in the East End and galvanised public opinion against the overcrowded, unsanitary slums. In the two decades after the murders, the worst of the slums were cleared and demolished, but the streets and some buildings survive and the legend of the Ripper is still promoted by guided tours of the murder sites. The Ten Bells public house in Commercial Street was frequented by at least one of the victims and was the focus of such tours for many years. In 2015, the Jack the Ripper Museum opened in east London.