The Shroud of Turin (Italian: Sindone di Torino), also known as the Holy Shroud (Italian: Sacra Sindone), is a length of linen cloth that bears a faint image of the front and back of a man. It has been venerated for centuries, especially by members of the Catholic Church, as the actual burial shroud used to wrap the body of Jesus of Nazareth after his crucifixion, and upon which Jesus's bodily image is miraculously imprinted. Its authenticity as a holy relic has been disputed even within the Catholic Church, and radiocarbon dating has shown it to be a medieval artifact. The human image on the shroud can be discerned more clearly in a black and white photographic negative than in its natural sepia color, an effect discovered in 1898 by Secondo Pia, who produced the first photographs of the shroud. This negative image is associated with a popular Catholic devotion to the Holy Face of Jesus.

The documented history of the shroud dates back to 1354, when it was exhibited in the new collegiate church of Lirey, a village in north-central France.^: 80–81 The shroud was denounced as a forgery by the bishop of Troyes in 1389.^: 90–96 It was acquired by the House of Savoy in 1453 and later deposited in a chapel in Chambéry,^{: 141–142, 153–154} where it was damaged by fire in 1532.^: 166 In 1578, the Savoys moved the shroud to their new capital in Turin, where it has remained ever since.^: 191 Since 1683, it has been kept in the Chapel of the Holy Shroud, which was designed for that purpose by architect Guarino Guarini and which is connected to both the royal palace and the Turin Cathedral.^: 233 Ownership of the shroud passed from the House of Savoy to the Catholic Church after the death of former king Umberto II in 1983.^: 415

Renowned microscopist Walter McCrone found, based on his examination of samples taken in 1978 from the surface of the shroud using adhesive tape, that the image on the shroud had been painted with a dilute solution of red ochre pigment in a gelatin medium. McCrone found no evidence of actual blood on the fabric, reporting instead that the apparent bloodstains were painted with vermilion pigment, also in a gelatin medium. McCrone's findings were disputed by other researchers and the nature of the image on the shroud continues to be debated.^{: 364–366}

In 1988, radiocarbon dating by three different laboratories established that the shroud's linen material was produced between the years 1260 and 1390 (to a 95% confidence level).^: 71–72 Defenders of the authenticity of the shroud have questioned those results, usually on the basis that the samples tested might have been contaminated or taken from a repair to the original fabric. Such fringe hypotheses have been refuted by carbon-dating experts and others based on evidence from the shroud itself, including the medieval repair hypothesis, the bio-contamination hypothesis and the carbon monoxide hypothesis. Though accepted as valid by experts, the carbon-dating of the shroud continues to generate significant public debate.^{: 424–445} The nature and history of the shroud have been the subjects of extensive and long-lasting controversies in both the scholarly literature and the popular press. Currently, the Catholic Church neither endorses nor rejects the authenticity of the shroud as a relic of Jesus. In 2013 Pope Francis referred to it as an "icon of a man scourged and crucified".